Boca Juniors gave their fading Apertura title hopes a boost with a 1-0 away win over leaders Velez Sarsfield.
Santiago Silva got the only goal of the match in the 31st minute to move Boca up to fourth place, five points adrift of their opponents.
Third-placed Newell's Old Boys failed to take advantage of Velez's slip as they lost 2-1 at home to All Boys.
Jonathan Ferrari put the visitors ahead after 13 minutes and Mauro Matos doubled the lead from the penalty spot in the 75th minute. Pablo Perez pulled a goal back for the hosts but it was not enough.
The loss could be costly in more ways than one for Old Boys, with key men Maxi Rodriguez and Gabriel Heinze both injured in the first half.
Colon Santa Fe are up to eighth after winning an ill-tempered derby match with Union Santa Fe 2-0.
Both teams had a man sent off, with Union losing Maximiliano Lugo after only 23 minutes.
Lucas Mugni put Colon 1-0 up on the stroke of half-time before Adrian Bastia took an early shower just after the hour mark, leaving Emmanuel Gigliotti to secure the win 20 minutes from time.
Arsenal Sarandi are just behind Colon on goal difference following a 3-0 win over Godoy Cruz, with Emilio Zelaya scoring a brace either side of Juan Pablo Caffa's strike.
The final two goals came after the visitors had two players sent off, with Nicolas Sanchez and Jorge Curbelo seeing red 10 minutes apart midway through the second half.
Tigre came from 2-0 down to salvage a draw away to San Martin San Juan, but their late attempts to win it were hampered by a red card for Ramiro Leone.
The hosts led 2-0 at the break thanks to goals from Humberto Osorio and Jorge Luna, but two goals in the space of five minutes from Silvio Gonzalez and Mariano Echeverria had it tied up with 20 minutes left. However, Leone saw red in the 79th minute as it ended all square.