Video caption: Highlights: Palmeiras stun River PlateHighlights: Palmeiras stun River Plate
Palmeiras put themselves within touching distance of the final with a stunning 3-0 win in Buenos Aires.
Goals from Rony and Luiz Adriano either side of half-time put the 1999 champions in a strong position before the hosts had Jorge Carrascal sent off on the hour mark, and Uruguayan left-back Matias Vina added a third shortly after.
Who are the teams?
Getty ImagesCopyright: Getty Images
River Plate's Ignacio Fernandez challenges Palmeiras' Gabriel Menino in the first legImage caption: River Plate's Ignacio Fernandez challenges Palmeiras' Gabriel Menino in the first leg
River Plate are looking to go one better than last season’s runners-up slot - but have a mountain to climb following the 3-0 thrashing in Buenos Aires last week. The 2015 and 2018 winners have reached the semi-finals five times in the last six attempts and if they reach their third successive final, they will be the first team to do so for 26 years.
Rafael Santos Borre has six goals for River – including the last three in the 6-2 second-leg demolition of Nacional, but another attacking player worthy of note is right-back Gonzalo Montiel, who has six assists in the tournament so far.
Three-time Copa Libertadores champions Palmeiras are the last unbeaten side in this year's tournament and have reached the semis for the second time in three years. Brazilian forward Rony has scored five goals including the opener in the first leg.
What is the Copa Libertadores?
The Copa Libertadores is South America's equivalent of the Champions League, featuring the most successful sides from across the continent.
It was founded in 1960, making this year's competition the 61st in its history.
Argentina's Independiente and Boca Juniors are the two most successful clubs in the competition's history. Independiente have won seven titles while Boca Juniors have reached a record 11 finals - winning the trophy six times.
Brazil's Flamengo are the current champions, but they were knocked out in the last 16 of this year's competition, which has been delayed due to the coronavirus.
The 2020 Copa Libertadores started in January but the group stages were halted in March and did not resume until September.
The competition is now down to the semi-final stage, with the final due to be played at the Maracana in Rio de Janeiro, Brazil, on 30 January.
How can I watch the Copa Libertadores?
All times in GMT & subject to change
BBC iPlayer
The BBC will show five more games from the 2020 Copa Libertadores, starting with two first-leg matches from the semi-finals.
The second legs of those semi-finals (13 January), and final at the Maracana in Rio de Janeiro, Brazil, on 30 January will also be shown.
All matches will be on the BBC Sport website, Red Button and iPlayer, where they will be available to catch up on for 30 days.
Wednesday 13 January
River Plate v Palmeiras, semi-final, second leg
00:20-02:30 - BBC Sport website and app, Red Button and BBC iPlayer
Boca Juniors v Santos, semi-final, second leg
22:05-00:15 - BBC Sport website and app, Red Button and BBC iPlayer
Live Reporting
All times stated are UK
Video caption: Highlights: Palmeiras stun River PlateHighlights: Palmeiras stun River Plate 
Getty ImagesCopyright: Getty Images River Plate's Ignacio Fernandez challenges Palmeiras' Gabriel Menino in the first legImage caption: River Plate's Ignacio Fernandez challenges Palmeiras' Gabriel Menino in the first leg 
Latest PostFirst Leg Highlights
Video content
Palmeiras put themselves within touching distance of the final with a stunning 3-0 win in Buenos Aires.
Goals from Rony and Luiz Adriano either side of half-time put the 1999 champions in a strong position before the hosts had Jorge Carrascal sent off on the hour mark, and Uruguayan left-back Matias Vina added a third shortly after.
Who are the teams?
River Plate are looking to go one better than last season’s runners-up slot - but have a mountain to climb following the 3-0 thrashing in Buenos Aires last week. The 2015 and 2018 winners have reached the semi-finals five times in the last six attempts and if they reach their third successive final, they will be the first team to do so for 26 years.
Rafael Santos Borre has six goals for River – including the last three in the 6-2 second-leg demolition of Nacional, but another attacking player worthy of note is right-back Gonzalo Montiel, who has six assists in the tournament so far.
Three-time Copa Libertadores champions Palmeiras are the last unbeaten side in this year's tournament and have reached the semis for the second time in three years. Brazilian forward Rony has scored five goals including the opener in the first leg.
What is the Copa Libertadores?
The Copa Libertadores is South America's equivalent of the Champions League, featuring the most successful sides from across the continent.
It was founded in 1960, making this year's competition the 61st in its history.
Argentina's Independiente and Boca Juniors are the two most successful clubs in the competition's history. Independiente have won seven titles while Boca Juniors have reached a record 11 finals - winning the trophy six times.
Brazil's Flamengo are the current champions, but they were knocked out in the last 16 of this year's competition, which has been delayed due to the coronavirus.
The 2020 Copa Libertadores started in January but the group stages were halted in March and did not resume until September.
The competition is now down to the semi-final stage, with the final due to be played at the Maracana in Rio de Janeiro, Brazil, on 30 January.
How can I watch the Copa Libertadores?
All times in GMT & subject to change
BBC iPlayer
The BBC will show five more games from the 2020 Copa Libertadores, starting with two first-leg matches from the semi-finals.
The second legs of those semi-finals (13 January), and final at the Maracana in Rio de Janeiro, Brazil, on 30 January will also be shown.
All matches will be on the BBC Sport website, Red Button and iPlayer, where they will be available to catch up on for 30 days.
Wednesday 13 January
River Plate v Palmeiras, semi-final, second leg
00:20-02:30 - BBC Sport website and app, Red Button and BBC iPlayer
Boca Juniors v Santos, semi-final, second leg
22:05-00:15 - BBC Sport website and app, Red Button and BBC iPlayer