River Plate beat fierce rivals Boca Juniors 2-0 in the first leg of their Copa Libertadores semi-final.
River Plate are the holders after beating their city rivals in the 2018 final, which was postponed after Boca's team bus was attacked by opposing fans then moved from Buenos Aires to Madrid.
River Plate went in front this time when Rafael Borre converted a penalty after the referee consulted with VAR.
An Ignacio Fernandez strike in the second half doubled the lead.
Boca midfielder Nicolas Capaldo, who blazed a shot over the bar with just the keeper to beat when his side were 1-0 down, was sent-off in injury-time after another VAR intervention.
The second leg at Boca will take place on 22 October.
Source: bbc