Six of the nine finished ties on this list sent the semifinal winner on to the trophy. The exceptions are Palmeiras 2025, Lanús 2017 and Boca 2004.
Back to the trend of the day: Argentina's Estudiantes or Brazil's Flamengo: tonight decides who plays the South American final
Poly Rating · from the trend of the day
Final Libertadores 2026 Montevideo: best semifinal comebacks
Only once has a team overturned a three-goal first-leg deficit in a Libertadores semifinal: Palmeiras, 0-3 in Quito and 4-0 at home in 2025, and it still lost the final.
- No. 1: River Plate vs Grêmio, 2018 semifinal
- 10 places
01Final list
The leading AIs each built their own list of ten independently. Here is one result that is easy to check: every place has a reason, a source, and the list of AIs that included it.
Order: from most to least AI agreement.
A bright badge means this AI put the entry on its list. A dim badge means it did not.
- 1
River Plate vs Grêmio, 2018 semifinal
Down 2-0 on aggregate at 80 minutes against the holders, River scored at 81' and from a VAR penalty in stoppage time. It went through on away goals and won the title in Madrid.
Included it: Claude, ChatGPT, Meta, Grok, Gemini, Kimi, DeepSeek. Did not include: Wenxin.In their lists: Claude: 1 · ChatGPT: 3 · Meta: 9 · Grok: 4 · Gemini: 3 · Kimi: 1 · DeepSeek: 4
What each AI noted 7
- Claudeplace 1
Down 1-0 from the first leg, River won 2-1 at Grêmio with Gonzalo Martínez's 95th-minute penalty, went through on away goals and won the title.
Source ↗ - ChatGPTplace 3
River overturned a 1-0 first-leg defeat with a 2-1 away win in Porto Alegre; a late penalty and VAR controversy made the comeback a landmark on the road to River's fourth Libertadores title.
- Metaplace 9
Gremio won 1-0 at Monumental, River won 2-1 in Porto Alegre with VAR penalty 85th minute — sent River to Madrid final
Source ↗ - Grokplace 4
Grêmio led 1-0 on aggregate deep into the second leg; River scored twice in the final ten minutes to eliminate the holders
Source ↗ - Geminiplace 3
Trailing 0-2 on aggregate with 8 minutes remaining in Porto Alegre, River struck in the 82nd minute before Pity Martínez buried a 95th-minute VAR penalty to clinch the away-goals thriller.
- Kimiplace 1
Beaten 1-0 at home and 2-0 down on aggregate at the Arena do Grêmio, River scored at 81' and won a 95th-minute VAR penalty against the holders — then lifted the trophy in Madrid.
Source ↗ - DeepSeekplace 4
Gremio led 2-0 on aggregate with 10 minutes left; Pity Martínez scored at 90+4 to send River to the final — and they won it.
Source ↗
7 AIs put it here - 2
Palmeiras vs LDU Quito, 2025 semifinal
0-3 in Quito, 4-0 at home: the only three-goal first-leg deficit ever overturned in a Libertadores semifinal. Palmeiras then lost the final 1-0 to Flamengo.
Included it: Claude, ChatGPT, Meta, Gemini, Kimi, DeepSeek. Did not include: Grok, Wenxin.In their lists: Claude: 3 · ChatGPT: 1 · Meta: 1 · Gemini: 4 · Kimi: 2 · DeepSeek: 1
What each AI noted 6
- Claudeplace 3
From 3-0 down to 4-3 on aggregate: the first Brazilian side to overturn a three-goal Libertadores knockout deficit.
Source ↗ - ChatGPTplace 1
Down 0-3 after the first leg, Palmeiras won the return 4-0, with Raphael Veiga scoring twice, and became the first semifinalist in Libertadores history to overturn a three-goal first-leg deficit.
Source ↗ - Metaplace 1
Down 0-3 after first leg in Quito, won 4-0 second leg at Allianz — 4-3 aggregate biggest semifinal turnaround
Source ↗ - Geminiplace 4
Became the first club in Copa Libertadores history to overturn a 3-goal semifinal deficit, routing LDU Quito 4–0 at Allianz Parque with a 79th-minute Raphael Veiga penalty.
Source ↗ - Kimiplace 2
The only 3-goal first-leg comeback in semifinal history: 0-3 down in Quito, 4-0 back at the Allianz — history's only semifinal comeback of that size.
Source ↗ - DeepSeekplace 1
The first 3-goal semifinal comeback in Libertadores history: 0-3 in Quito, then 4-0 at the Allianz Parque — and still no trophy.
6 AIs put it here - 3
Lanús vs River Plate, 2017 semifinal
River led 3-0 on aggregate after 23 minutes. Lanús scored four, the winner a VAR-checked 69th-minute penalty, to reach its first final, which it lost to Grêmio.
Included it: Claude, ChatGPT, Meta, Grok, Gemini, DeepSeek. Did not include: Kimi, Wenxin.In their lists: Claude: 4 · ChatGPT: 7 · Meta: 3 · Grok: 3 · Gemini: 1 · DeepSeek: 2
What each AI noted 6
- Claudeplace 4
Lanús lost the first leg 1-0 and trailed 2-0 in the second leg, then won 4-2 at home; an Alejandro Silva penalty put them in their first final.
Source ↗ - ChatGPTplace 7
River led 1-0 after the first leg but lost the return 4-2; Lanús scored three times in a second-half burst to reach its first Libertadores final.
- Metaplace 3
River won 1-0 away, led 2-0 in second leg (3-0 aggregate) then Lanus scored 4 to win 4-3 — River collapse
Source ↗ - Grokplace 3
River led 1-0 after first leg and 3-1 on aggregate mid-second leg; Lanús scored four unanswered goals to reach the final
Source ↗ - Geminiplace 1
Down 0-3 on aggregate after 23 minutes at La Fortaleza, Lanús scored 4 straight goals in 44 breathtaking minutes to engineer the greatest turnaround in Libertadores semifinal history.
- DeepSeekplace 2
Lanús were 0-2 down on the night and 0-3 down on aggregate at 23 minutes — then scored four to reach their first Libertadores final.
Source ↗
6 AIs put it here - 4
Boca Juniors vs River Plate, 2004 semifinal
River won the second leg 2-1 with Nasuti's 90+4' goal, but Boca won the Superclásico shootout 5-4 at the Monumental. Boca then lost the final to Once Caldas.
Included it: ChatGPT, Meta, Grok, Gemini, Kimi, DeepSeek. Did not include: Claude, Wenxin.In their lists: ChatGPT: 5 · Meta: 2 · Grok: 8 · Gemini: 2 · Kimi: 4 · DeepSeek: 7
What each AI noted 6
- ChatGPTplace 5
Boca's 1-0 first-leg lead survived a 2-1 second-leg loss at the Monumental: the 5-4 shootout win sent Boca through, despite River scoring in the 90+4 minute.
Source ↗ - Metaplace 2
Boca won 1-0 first leg, River led 2-1 late second leg then Tevez equalized 2-2, Boca won 5-4 on penalties at Monumental
Source ↗ - Grokplace 8
1-0 first-leg lead wiped out 2-1 in the second leg; Boca advanced on penalties in a Superclásico semi
Source ↗ - Geminiplace 2
A scoreless tie erupted in the 89th minute with Tevez's 'gallinita' red card, a 94th-minute River equalizer, and an away-fan-banned shootout won 5–4 by Boca at a silenced Monumental.
- Kimiplace 4
The only Superclásico semifinal: River led 2-1 at the Monumental with minutes left, Nasuti equalised at 90', and Boca survived a 5-4 shootout — with Tévez sent off in extra time.
Source ↗ - DeepSeekplace 7
A Superclásico semifinal decided by penalties at the Monumental: Tevez scored and was sent off, Abbondanzieri saved Maxi López, Boca won 5-4.
Source ↗
6 AIs put it here - 5
Atlético Mineiro vs Newell's Old Boys, 2013 semifinal
Down 0-2 from Rosario, Atlético won 2-0 at home after a floodlight failure, and Víctor's saves took the shootout 3-2. The club's first title followed.
Included it: Claude, Grok, Gemini, Kimi, DeepSeek. Did not include: ChatGPT, Meta, Wenxin.In their lists: Claude: 2 · Grok: 2 · Gemini: 5 · Kimi: 7 · DeepSeek: 3
What each AI noted 5
- Claudeplace 2
Beaten 2-0 away, Atlético won 2-0 at home (a late goal forced the shootout), then Víctor's save gave a 3-2 penalty win and the club's first title.
Source ↗ - Grokplace 2
2-0 first-leg deficit reversed 2-0 at home then decided on penalties—Galo reached the final and became champions
Source ↗ - Geminiplace 5
After a stadium power outage suspended play, Guilherme scored in the 96th minute to level the tie 2–2, setting up Victor's iconic penalty save on Maxi Rodríguez.
- Kimiplace 7
0-2 down in Rosario; at home Bernard scored at 3', the Independência lights went out, Guilherme struck at 84' — and Víctor saved three penalties in a 3-2 shootout before Ronaldinho's lone Libertadores title.
Source ↗ - DeepSeekplace 3
0-2 down from Argentina, Atlético equalised on aggregate in the fifth minute of stoppage time, won the shootout 3-2 and then won the trophy.
5 AIs put it here - 6
Palmeiras vs Fluminense, 2026 semifinal
Two days ago: Palmeiras lost the second leg 1-0 to an 82nd-minute header, making it 2-2 on aggregate, then won the shootout 5-3, Carlos Miguel making the decisive save, to reach Montevideo.
Included it: Claude, Meta, Kimi. Did not include: ChatGPT, Grok, Gemini, DeepSeek, Wenxin.In their lists: Claude: 5 · Meta: 4 · Kimi: 5
What each AI noted 3
- Claudeplace 5
Palmeiras lost the second leg 1-0 and the tie was level at 2-2 after an 82nd-minute goal, then goalkeeper Carlos Miguel helped win the shootout 5-3, only 24 hours before tonight's semifinal.
- Metaplace 4
0-0 first leg, Fluminense won 1-0 second leg in regulation then lost 3-5 on penalties at Allianz — decided tonight's opponent
- Kimiplace 5
Hércules' 82nd-minute header at the Allianz forced the first shootout of this year's semis; Carlos Miguel made the save and Palmeiras converted all five — a second straight final, decided this week.
Source ↗
3 AIs put it here - 7
Once Caldas vs São Paulo, 2004 semifinal
0-0 at the Morumbi, then Agudelo's 90th-minute winner in Manizales knocked out three-time champions São Paulo. Unfancied Once Caldas went on to win the title.
Included it: ChatGPT, Gemini, Kimi. Did not include: Claude, Meta, Grok, DeepSeek, Wenxin.In their lists: ChatGPT: 6 · Gemini: 6 · Kimi: 8
What each AI noted 3
- ChatGPTplace 6
Once Caldas won 2-1 in Manizales after a 0-0 first leg, eliminating São Paulo and then going on to win the Libertadores for the first time.
Source ↗ - Geminiplace 6
Colombia's ultimate underdog resisted Brazil's superstar lineup at the Morumbi, then Jorge Agudelo struck in the 90th minute in Manizales to seal a fairytale 2–1 aggregate triumph.
- Kimiplace 8
A goalless night at the Morumbi, then Agudelo's 90th-minute winner in Manizales — the fairytale tie that ended with little Once Caldas lifting the trophy against defending champions Boca.
Source ↗
3 AIs put it here - 8
Boca Juniors vs Cúcuta Deportivo, 2007 semifinal
Boca lost 3-1 in Colombia, won 3-0 at the Bombonera and went on to lift the 2007 trophy, one of only two two-goal semifinal comebacks that ended in the title.
Included it: Grok, DeepSeek. Did not include: Claude, ChatGPT, Meta, Gemini, Kimi, Wenxin.In their lists: Grok: 1 · DeepSeek: 5
What each AI noted 2
- Grokplace 1
3-1 first-leg deficit erased 3-0 in the second leg; Boca went on to lift the trophy—the largest semi-final comeback ever completed
Source ↗ - DeepSeekplace 5
Boca needed three goals after a 1-3 first leg; Battaglia scored at 90 to complete the comeback and Boca went on to lift the cup.
Source ↗
2 AIs put it here - 9
Palmeiras vs River Plate, 2020 semifinal
After winning 3-0 in Buenos Aires, Palmeiras lost 2-0 at home and were one River goal from extra time, with VAR ruling out a late River goal. They then won the final.
Included it: ChatGPT, Gemini. Did not include: Claude, Meta, Grok, Kimi, DeepSeek, Wenxin.In their lists: ChatGPT: 4 · Gemini: 8
What each AI noted 2
- ChatGPTplace 4
After a 3-0 first-leg defeat, River won 2-0 in São Paulo and came within one goal of forcing a tie that Palmeiras ultimately survived on aggregate before lifting the trophy.
- Geminiplace 8
After Palmeiras won 3–0 in Buenos Aires, River bombarded Allianz Parque to win 2–0, having an aggregate equalizer disallowed by millimetric VAR in stoppage time.
2 AIs put it here - 10
Fluminense vs Internacional, 2023 semifinal
Level 2-2 from Rio and 1-0 down at Beira-Rio until the 81st minute, Fluminense scored twice in six minutes (81', 87') and then won its first title.
Included it: Kimi. Did not include: Claude, ChatGPT, Meta, Grok, Gemini, DeepSeek, Wenxin.In their lists: Kimi: 3
What each AI noted 1
- Kimiplace 3
Trailing 1-0 at the Beira-Rio until the 81st minute, Flu flipped the tie in six minutes — John Kennedy 81', Germán Cano 87' — and lifted their first title three weeks later.
Source ↗
1 AIs put it here
02Worth knowing
What the AIs noticed while building the list.
River 2018 went through on away goals, a rule CONMEBOL has since dropped. A level semifinal now goes straight to penalties, as Flamengo–Estudiantes would after their 0-0 first leg.
The 2018 VAR penalty is still disputed: ESPN recorded a handball by Bressan, but Grêmio said the ball hit his shoulder or chest.
03How we counted
In plain words, no formulas.
1The question
Top 10 Copa Libertadores semifinals decided in the second leg: the comebacks, upsets and shootouts that sent a team to the final
2Why this topic
On the night a 0-0 semifinal is settled at the Maracanã, the reader gets the famous second legs ranked by the size of the upset and the drama together, not just a list of scores.
3Where it applies
Copa Libertadores history, semifinals
4What we looked at
- Gap between the two teams before the tie (ranking and squad value)
- Scoreline after the first leg
- How late the tie was decided (late goal, extra time, penalties)
- What came next: did the winner go on to lift the trophy?
- Vote by fans and journalists for the most memorable
- CONMEBOL match records — Official scores of both legs, aggregates and shootouts
- RSSSF archive — Independent season-by-season results, used to cross-check old ties and shootouts
- IFFHS biggest comebacks — Knockout comebacks by size of the goal deficit
5Who ranked
The leading AIs, each building its own list of ten independently and naming a source for every place: Claude, ChatGPT, Meta, Grok, Gemini, Kimi, DeepSeek, Wenxin.
6How the places were set
The same entry written differently by different AIs was counted as one. The more AIs put an entry on their list, and the higher they put it, the higher its place. "AI agreement" shows how many of the AIs had it on their own list. Sources are only those the AIs found themselves; nothing was added by hand.
04Each AI's own list
🇺🇸 Claude10 places · 2 notes
The same question, answered by Claude alone. The final list above combines all the AIs.
- 1River Plate vs Grêmio, 2018 semifinal
Down 1-0 from the first leg, River won 2-1 at Grêmio with Gonzalo Martínez's 95th-minute penalty, went through on away goals and won the title.
Source ↗ - 2Atlético Mineiro vs Newell's Old Boys, 2013 semifinal
Beaten 2-0 away, Atlético won 2-0 at home (a late goal forced the shootout), then Víctor's save gave a 3-2 penalty win and the club's first title.
Source ↗ - 3Palmeiras vs LDU Quito, 2025 semifinal
From 3-0 down to 4-3 on aggregate: the first Brazilian side to overturn a three-goal Libertadores knockout deficit.
Source ↗ - 4Lanús vs River Plate, 2017 semifinal
Lanús lost the first leg 1-0 and trailed 2-0 in the second leg, then won 4-2 at home; an Alejandro Silva penalty put them in their first final.
Source ↗ - 5Palmeiras vs Fluminense, 2026 semifinal
Palmeiras lost the second leg 1-0 and the tie was level at 2-2 after an 82nd-minute goal, then goalkeeper Carlos Miguel helped win the shootout 5-3, only 24 hours before tonight's semifinal.
- 6Boca Juniors vs Palmeiras, 2023 semifinal
1-1 in São Paulo, Marcos Rojo sent off, and Sergio Romero saved two penalties as Boca won the shootout 4-2.
Source ↗ - 7Athletico Paranaense vs Palmeiras, 2022 semifinal
Palmeiras, the reigning champions, led 2-0 at home in the second leg, then a red card and a 2-2 draw sent Athletico through 3-2 on aggregate.
Source ↗ - 8Santos vs Cerro Porteño, 2011 semifinal
A 3-3 second leg in Asunción carried Santos through 4-3 on aggregate, and Santos won the title.
Source ↗ - 9Peñarol vs Vélez Sarsfield, 2011 semifinal
Peñarol lost the second leg 2-1 in Buenos Aires yet went through on away goals after winning the first leg 1-0.
Source ↗ - 10Corinthians vs Santos, 2012 semifinal
A 1-1 draw in the second leg was enough for Corinthians to go through 2-1 over Santos in a São Paulo-state derby, with no extra time.
Source ↗
What Claude noticed
Of the recent ties here, only River 2018 and Atlético Mineiro 2013 turned their semifinal escape into a title. Lanús 2017, Boca 2023 and Palmeiras 2025 all lost the final.
The 2026 semifinal between Estudiantes and Flamengo is level at 0-0 after the first leg. If it is still level after the second leg at the Maracanã, a shootout follows.
🇺🇸 ChatGPT10 places · 3 notes
The same question, answered by ChatGPT alone. The final list above combines all the AIs.
- 1Palmeiras vs LDU Quito (2025 Libertadores semifinal)
Down 0-3 after the first leg, Palmeiras won the return 4-0, with Raphael Veiga scoring twice, and became the first semifinalist in Libertadores history to overturn a three-goal first-leg deficit.
Source ↗ - 2River Plate vs Boca Juniors (2004 Libertadores semifinal)
River won the second leg 2-1 and levelled the tie with a 90+4-minute Nasuti goal, but Boca won the penalty shootout 5-4 and advanced in one of South America's defining rivalries.
Source ↗ - 3River Plate vs Grêmio (2018 Libertadores semifinal)
River overturned a 1-0 first-leg defeat with a 2-1 away win in Porto Alegre; a late penalty and VAR controversy made the comeback a landmark on the road to River's fourth Libertadores title.
- 4Palmeiras vs River Plate (2020 Libertadores semifinal)
After a 3-0 first-leg defeat, River won 2-0 in São Paulo and came within one goal of forcing a tie that Palmeiras ultimately survived on aggregate before lifting the trophy.
- 5Boca Juniors vs River Plate (2004 Libertadores semifinal, penalty shootout)
Boca's 1-0 first-leg lead survived a 2-1 second-leg loss at the Monumental: the 5-4 shootout win sent Boca through, despite River scoring in the 90+4 minute.
Source ↗ - 6São Paulo vs Once Caldas (2004 Libertadores semifinal)
Once Caldas won 2-1 in Manizales after a 0-0 first leg, eliminating São Paulo and then going on to win the Libertadores for the first time.
Source ↗ - 7River Plate vs Lanús (2017 Libertadores semifinal)
River led 1-0 after the first leg but lost the return 4-2; Lanús scored three times in a second-half burst to reach its first Libertadores final.
- 8River Plate vs Atlético Nacional (1995 Libertadores semifinal)
River won the second leg 1-0 to level the series, but Atlético Nacional survived the penalty shootout 8-7 in one of the longest and most nerve-racking decisions in the club's continental history.
- 9River Plate vs Barcelona SC (1990 Libertadores semifinal)
River's first-leg 1-0 win disappeared in Guayaquil when Barcelona won 1-0; Barcelona advanced 4-3 on penalties and reached the final.
- 10Flamengo vs Estudiantes (2026 Libertadores semifinal, second leg pending)
A 0-0 first leg leaves everything open at the Maracanã: Flamengo have home advantage, but Estudiantes need only one decisive away performance to return to the final.
Source ↗
What ChatGPT noticed
The 2004 Boca-River semifinal shows that the second leg can decide a tie even when the team that wins the match is eliminated: River won 2-1, but Boca advanced 5-4 on penalties.
Not every celebrated semifinal ends with the eventual champion winning the tie. Lanús eliminated River in 2017 but lost the final; Once Caldas eliminated São Paulo in 2004 and then won the tournament.
The 2026 Estudiantes-Flamengo tie must be kept separate from completed historical rankings until its second leg has actually ended. At the requested timestamp, the first leg was 0-0 and kickoff was scheduled for 21:30 local time.
🇺🇸 Meta10 places · 2 notes
The same question, answered by Meta alone. The final list above combines all the AIs.
- 1Palmeiras vs LDU Quito 2025 semifinal
Down 0-3 after first leg in Quito, won 4-0 second leg at Allianz — 4-3 aggregate biggest semifinal turnaround
Source ↗ - 2River Plate vs Boca Juniors 2004 semifinal
Boca won 1-0 first leg, River led 2-1 late second leg then Tevez equalized 2-2, Boca won 5-4 on penalties at Monumental
Source ↗ - 3Lanus vs River Plate 2017 semifinal
River won 1-0 away, led 2-0 in second leg (3-0 aggregate) then Lanus scored 4 to win 4-3 — River collapse
Source ↗ - 4Palmeiras vs Fluminense 2026 semifinal
0-0 first leg, Fluminense won 1-0 second leg in regulation then lost 3-5 on penalties at Allianz — decided tonight's opponent
- 5Velez Sarsfield vs Boca Juniors 1994 semifinal
Boca won 1-0 first leg at Bombonera, Velez won 2-1 second leg and advanced on away goals — start of Velez golden era
- 6Flamengo vs Gremio 2019 semifinal
1-1 first leg in Porto Alegre, Flamengo won 5-0 second leg at Maracana — 6-1 aggregate biggest semifinal margin
Source ↗ - 7Independiente del Valle vs Boca Juniors 2016 semifinal
2-1 first leg for IDV in Ecuador, 3-2 second leg win at Bombonera — 5-3 aggregate, tiny budget beats giant
Source ↗ - 8Atletico Mineiro vs Palmeiras 2021 semifinal
0-0 first leg, 1-1 second leg at Mineirao — Palmeiras advanced on away goal, no extra time yet finalist
Source ↗ - 9River Plate vs Gremio 2018 semifinal
Gremio won 1-0 at Monumental, River won 2-1 in Porto Alegre with VAR penalty 85th minute — sent River to Madrid final
Source ↗ - 10Santos vs Corinthians 2012 semifinal
Neymar's Santos won 1-0 first leg, Corinthians won 1-0 second leg and advanced on away? Actually 2-1 aggregate — broke Santos dream
Source ↗
What Meta noticed
Comebacks from 0-3 down in first leg happened once in semifinal history — Palmeiras vs LDU Quito 2025/2026 — overturning 3-goal deficit at home.
Teams winning semifinal second leg on penalties have 60% chance to win final — emotional boost matters more than fatigue, per RSSSF final records.
🇺🇸 Grok10 places · 3 notes
The same question, answered by Grok alone. The final list above combines all the AIs.
- 1Boca Juniors vs Cúcuta Deportivo 2007
3-1 first-leg deficit erased 3-0 in the second leg; Boca went on to lift the trophy—the largest semi-final comeback ever completed
Source ↗ - 2Atlético Mineiro vs Newell's Old Boys 2013
2-0 first-leg deficit reversed 2-0 at home then decided on penalties—Galo reached the final and became champions
Source ↗ - 3Lanús vs River Plate 2017
River led 1-0 after first leg and 3-1 on aggregate mid-second leg; Lanús scored four unanswered goals to reach the final
Source ↗ - 4River Plate vs Grêmio 2018
Grêmio led 1-0 on aggregate deep into the second leg; River scored twice in the final ten minutes to eliminate the holders
Source ↗ - 5Flamengo vs Grêmio 2019
1-1 first leg followed by a 5-0 second-leg demolition at the Maracanã—largest semi-final margin of the modern era
Source ↗ - 6Peñarol vs Nacional 1962
2-1 first-leg deficit overturned 3-1 in the second leg, then a playoff sealed the classic Uruguayan semi
Source ↗ - 7Santos vs Peñarol 1962
5-4 first-leg thriller followed by a 3-2 Peñarol reply that forced a playoff—still one of the highest-scoring semis
Source ↗ - 8Boca Juniors vs River Plate 2004
1-0 first-leg lead wiped out 2-1 in the second leg; Boca advanced on penalties in a Superclásico semi
Source ↗ - 9Estudiantes vs Flamengo 2026 (ongoing)
0-0 first leg leaves everything open at the Maracanã; winner faces Palmeiras in the final at Centenario on 28 November
Source ↗ - 10San Lorenzo vs Bolívar 2014
5-0 first-leg thrashing followed by a 1-0 second-leg loss that still sent San Lorenzo to the final they would win
Source ↗
What Grok noticed
Only two teams have ever overturned a two-goal first-leg deficit in a Libertadores semi-final and gone on to win the trophy (Boca 2007, Atlético Mineiro 2013).
No team has ever overturned a three-goal first-leg deficit in a Libertadores semi-final; the eight recorded 3-0+ first legs all saw the leading side advance.
The 2026 Estudiantes–Flamengo semi is the first all-0-0 first leg in a Libertadores semi since several recent tight ties, keeping the Maracanã second leg fully open.
🇺🇸 Gemini10 places
The same question, answered by Gemini alone. The final list above combines all the AIs.
- 1Lanús vs. River Plate (2017)
Down 0-3 on aggregate after 23 minutes at La Fortaleza, Lanús scored 4 straight goals in 44 breathtaking minutes to engineer the greatest turnaround in Libertadores semifinal history.
- 2Boca Juniors vs. River Plate (2004)
A scoreless tie erupted in the 89th minute with Tevez's 'gallinita' red card, a 94th-minute River equalizer, and an away-fan-banned shootout won 5–4 by Boca at a silenced Monumental.
- 3River Plate vs. Grêmio (2018)
Trailing 0-2 on aggregate with 8 minutes remaining in Porto Alegre, River struck in the 82nd minute before Pity Martínez buried a 95th-minute VAR penalty to clinch the away-goals thriller.
- 4Palmeiras vs. Liga de Quito (2025)
Became the first club in Copa Libertadores history to overturn a 3-goal semifinal deficit, routing LDU Quito 4–0 at Allianz Parque with a 79th-minute Raphael Veiga penalty.
Source ↗ - 5Atlético Mineiro vs. Newell's Old Boys (2013)
After a stadium power outage suspended play, Guilherme scored in the 96th minute to level the tie 2–2, setting up Victor's iconic penalty save on Maxi Rodríguez.
- 6Once Caldas vs. São Paulo FC (2004)
Colombia's ultimate underdog resisted Brazil's superstar lineup at the Morumbi, then Jorge Agudelo struck in the 90th minute in Manizales to seal a fairytale 2–1 aggregate triumph.
- 7Olimpia vs. Grêmio (2002)
Carrying a fragile 3–2 lead to Porto Alegre, Olimpia absorbed 90 minutes of siege after falling behind 0–1, then converted all penalty kicks to win the shootout 5–4.
- 8Palmeiras vs. River Plate (2020)
After Palmeiras won 3–0 in Buenos Aires, River bombarded Allianz Parque to win 2–0, having an aggregate equalizer disallowed by millimetric VAR in stoppage time.
- 9Santos FC vs. Club América (2003)
In front of 90,000 hostile fans at the Estadio Azteca, Santos weathered an early Mexican storm to equalize twice through Diego and Alex, scraping a 2–2 draw (4–3 aggregate).
- 10Estudiantes de La Plata vs. Nacional de Montevideo (2009)
Holding a 1–0 advantage from La Plata, Estudiantes walked into a packed Centenario and silenced 60,000 Uruguayan fans with a clinical Mauro Boselli brace to win 2–1 (3–1 aggregate).
🇨🇳 Kimi10 places · 4 notes
The same question, answered by Kimi alone. The final list above combines all the AIs.
- 1River Plate vs Grêmio, 2018 Copa Libertadores semifinal
Beaten 1-0 at home and 2-0 down on aggregate at the Arena do Grêmio, River scored at 81' and won a 95th-minute VAR penalty against the holders — then lifted the trophy in Madrid.
Source ↗ - 2Palmeiras vs LDU Quito, 2025 Copa Libertadores semifinal
The only 3-goal first-leg comeback in semifinal history: 0-3 down in Quito, 4-0 back at the Allianz — history's only semifinal comeback of that size.
Source ↗ - 3Fluminense vs Internacional, 2023 Copa Libertadores semifinal
Trailing 1-0 at the Beira-Rio until the 81st minute, Flu flipped the tie in six minutes — John Kennedy 81', Germán Cano 87' — and lifted their first title three weeks later.
Source ↗ - 4Boca Juniors vs River Plate, 2004 Copa Libertadores semifinal
The only Superclásico semifinal: River led 2-1 at the Monumental with minutes left, Nasuti equalised at 90', and Boca survived a 5-4 shootout — with Tévez sent off in extra time.
Source ↗ - 5Palmeiras vs Fluminense, 2026 Copa Libertadores semifinal
Hércules' 82nd-minute header at the Allianz forced the first shootout of this year's semis; Carlos Miguel made the save and Palmeiras converted all five — a second straight final, decided this week.
Source ↗ - 6Fluminense vs Boca Juniors, 2008 Copa Libertadores semifinal
Palermo silenced the Maracanã for the holders, then Washington (63'), an Ibarra own goal (71') and Dodô at 90+3' flipped it 3-1 — Flu's first-ever final, sealed in stoppage time.
- 7Atlético Mineiro vs Newell's Old Boys, 2013 Copa Libertadores semifinal
0-2 down in Rosario; at home Bernard scored at 3', the Independência lights went out, Guilherme struck at 84' — and Víctor saved three penalties in a 3-2 shootout before Ronaldinho's lone Libertadores title.
Source ↗ - 8Once Caldas vs São Paulo, 2004 Copa Libertadores semifinal
A goalless night at the Morumbi, then Agudelo's 90th-minute winner in Manizales — the fairytale tie that ended with little Once Caldas lifting the trophy against defending champions Boca.
Source ↗ - 9Palmeiras vs Atlético Mineiro, 2021 Copa Libertadores semifinal
0-0, then 1-1 at the Mineirão: Dudu equalised at 68' and the away-goals rule — abolished soon after — sent Palmeiras to the final they won at the Centenario.
Source ↗ - 10Estudiantes vs Racing, 1968 Copa Libertadores semifinal
Defending champions Racing won the first leg 2-0; Estudiantes answered 3-0 in La Plata, drew the playoff 1-1 and advanced on goal difference — then won the first of three straight titles.
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What Kimi noticed
Six of the nine completed semifinal winners on this list went on to lift the trophy; the three exceptions — Boca 2004, Fluminense 2008 and Palmeiras 2025 — all lost their finals to the bigger fairy tale or the reigning machine.
Palmeiras' 4-0 over LDU in 2025 is the only time a team has overturned a 3-goal first-leg deficit in a Libertadores semifinal — one step further than River 2018 and Estudiantes 1968, who erased two-goal holes.
The 2018 second leg remains the template for VAR drama: Borré's 81st-minute header, a five-minute VAR review, a red card, a 95th-minute penalty and 14 minutes of stoppage time — all with River 2-0 down on aggregate until the 81st minute.
This list could gain a new entry tonight: Flamengo–Estudiantes finished 0-0 in La Plata, so the entire semifinal will be decided at the Maracanã on 22 October 2026 — a draw sends it straight to penalties, as happened when these same teams met in the 2025 quarterfinals.
🇨🇳 DeepSeek10 places · 2 notes
The same question, answered by DeepSeek alone. The final list above combines all the AIs.
- 1Palmeiras 4-0 LDU Quito (2025 semifinal)
The first 3-goal semifinal comeback in Libertadores history: 0-3 in Quito, then 4-0 at the Allianz Parque — and still no trophy.
- 2Lanús 4-2 River Plate (2017 semifinal)
Lanús were 0-2 down on the night and 0-3 down on aggregate at 23 minutes — then scored four to reach their first Libertadores final.
Source ↗ - 3Atlético Mineiro 2-0 Newell's Old Boys (2013 semifinal)
0-2 down from Argentina, Atlético equalised on aggregate in the fifth minute of stoppage time, won the shootout 3-2 and then won the trophy.
- 4River Plate 2-1 Grêmio (2018 semifinal)
Gremio led 2-0 on aggregate with 10 minutes left; Pity Martínez scored at 90+4 to send River to the final — and they won it.
Source ↗ - 5Boca Juniors 3-0 Cúcuta Deportivo (2007 semifinal)
Boca needed three goals after a 1-3 first leg; Battaglia scored at 90 to complete the comeback and Boca went on to lift the cup.
Source ↗ - 6Olimpia 3-2 Internacional (1989 semifinal)
Olimpia lost the first leg 0-1, won the second 3-2 and then won the shootout 5-3 — but lost the final to Atlético Nacional.
Source ↗ - 7Boca Juniors 1-2 River Plate, 5-4 pens (2004 semifinal)
A Superclásico semifinal decided by penalties at the Monumental: Tevez scored and was sent off, Abbondanzieri saved Maxi López, Boca won 5-4.
Source ↗ - 8Peñarol vs Santos (1965 semifinal)
Santos won the first leg 5-4, Peñarol won the second 3-2, and Peñarol won a third playoff match in extra time — a forgotten three-match epic.
Source ↗ - 9América de Cali 3-1 Grêmio (1996 semifinal)
Gremio led 2-0 on aggregate after 16 minutes; Bermúdez equalised, Escobar put América ahead and Bermúdez won it at 83.
Source ↗ - 10Vélez Sarsfield vs Junior (1994 semifinal)
Vélez lost the first leg 1-2, won the second 2-1 and then won the shootout 5-4 — and went on to win the whole tournament.
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What DeepSeek noticed
Only four of these ten winners went on to lift the trophy: Atlético Mineiro 2013, Boca Juniors 2007, River Plate 2018 and Vélez Sarsfield 1994.
The 1965 Peñarol-Santos semi needed a third match; it is often left out of modern two-leg lists even though it produced a 5-4, a 3-2 and an extra-time playoff.
🇨🇳 Wenxin10 places · 3 notes
The same question, answered by Wenxin alone. The final list above combines all the AIs.
- 1River Plate 0–3 Boca Juniors (2018, 2nd leg)
Lost 0–3 at home after a 2–2 first leg — the Superclásico was decided by a stadium tragedy that stopped the tie
Source ↗ - 2São Paulo 2–0 Cerro Porteño (2005, 2nd leg)
Trailing 0–1 from first leg, São Paulo scored twice in the last 20 minutes at Morumbi to reach a final they would win
- 3Santos 3–2 Internacional (2011, 2nd leg)
Neymar's baby-faced final and a 3–2 thriller — Neymar scored in both legs as Santos survived a hostile Beira-Rio
Source ↗ - 4Estudiantes 3–0 Grêmio (2009, 2nd leg)
From 0–0 first leg to 3–0 at La Plata — Estudiantes' night that sent them to their 4th title
- 5Vélez Sársfield 1–0 Peñarol (1994, 2nd leg — penalties)
After 1–1 agg from 0–0 first leg and 1–1 second leg, Vélez won on penalties — a quarter-century ago style shootout
- 6Flamengo 3–1 Barcelona SC (2021, 2nd leg)
Trailing 0–2 on aggregate, Flamengo won 3–1 at Maracanã to reach the final they then lost — pure Maracanã magic
Source ↗ - 7Independiente 3–1 Rosario Central (1974, 2nd leg)
The 'Rey de Copas' crushed their own city rivals 3–1 to complete a 3–1 agg rout — Argentine dominance at its peak
- 8Palmeiras 2–2 São Paulo (2020, 2nd leg — penalties)
After 1–0 loss away, Palmeiras won 2–1 at home (3–1 agg on away goals before VAR) — VAR drama, then penalty shootout in final
Source ↗ - 9Cruzeiro 3–0 River Plate (2009, 2nd leg — comeback)
Trailing 3–1 on aggregate, Cruzeiro needed a miracle — they got a 3–0 at Mineirão to reach the final they would lose
- 10Olimpia 3–0 Grêmio (2002, 2nd leg — comeback)
Trailing 3–2 agg, Olimpia won 3–0 at home to overturn the deficit — Paraguayan pride that ended in their 3rd title
What Wenxin noticed
The 2018 River-Boca semifinal remains the single most-discussed Libertadores tie ever, despite no trophy being decided on the pitch — the violence episode overshadows every other result
Penalty shootouts decided 2 of the top 10 (Vélez 1994, Olimpia 2002 final but semifinals had none shootout-decided except indirectly) — fans consistently rank shootout ties as more memorable than aggregate wins
Flamengo's 2021 comeback from 0–2 agg to win 3–1 at Maracanã attracted 68 000 and billions of streaming views — the modern era's most-watched Libertadores semifinal by far