Martin Perez Guedes opened the scoring for Olimpo in the 7th minute, finishing at the near post after a deflected shot rolled into his path. Agustin Vuletich extended the lead in the 70th from close range, with Perez Guedes completing the scoring with his second shortly after.
Osvaldo Noe netted from two yards (meters) in the 29th for Argentinos after a right wing cross was flicked on and he found himself in front of an open goal.
All Boys had Roberto Battion sent off in the 62nd, when he picked up his second yellow card in four minutes.
River Plate won for the first time in four matches in a dominant display against Tigre after Manuel Lanzini opened the scoring less than a minute after halftime.
Giovanni Simeone pounced on a defensive error to add River's second in the 63rd, before Lanzini wrapped up the scoring two minutes later.