Fernando Curuchet's side managed to respond to Alfredo Armua's 20th-minute goal and claimed their first win in two games. Nicolas Correa equalised in the 35th minute and, immediately after the interval, Felipe Gedoz put Defensor ahead thanks to an Olivera assist.
Ramua was shown a red card in the 65th minute and things soon became easier for Defensor, who made it 3-1 four minutes later as Olivera finished off a counter-attack. Four minutes from time, Olivera netted his second goal. Defensor duly moved level with Universidad de Chile and Real Garcilaso at the top of Group 5.
Meanwhile, Mexico's Leon failed to profit from a large number of scoring opportunities and only got a 1-1 draw from their trip to Bolivar. Argentinian striker Mauro Boselli put Leon ahead in the second minute after Luis Montes stole the ball from defenders but Juan Miguel Callejon equalised for Bolivar in the 66th minute.
Leon could have won the game with seven minutes to go, but Rafael Marquez missed a penalty. The draw means Leon head Group 7 with four points, one more than Ecuador's Emelec, who play Flamengo in Brazil next week.
Finally, in Chile, a Yerson Opazo goal with eight minutes remaining gave hosts O'Higgins a 1-0 win over Colombia's Cali. The Chilean champions have taken control of Group 3 with four points and sit just above Cali.