Boca Juniors went to the top of the Apertura with a 2-1 win over a Union Santa Fe side who finished with nine men.
Boca's third win in four league games this season was secured by goals from Rolando Schiavi and Nicolas Blandi.
Schiavi put visitors Boca ahead after 19 minutes with a powerful header from eight yards, before Union had Pablo Bruna sent off in the 35th minute.
Despite their reduced numbers, Union drew level in the 61st minute when Nicolas Correa met a corner from the right with a firm header that went in at the near post.
Union lost a second man in the 71st minute when Mauro Maidana was ordered off, and Blandi denied the hosts a point when he tucked the ball in from close range in the 88th minute after a shot came back off the crossbar. Union have lost four from four so far.
Unbeaten Arsenal Sarandi stand second in the table after a 2-0 win at Independiente.
Eduardo Tuzzio's own goal broke the deadlock in the 83rd minute, as he reached to clear a cross from the right but turned the ball past goalkeeper Hilario Navarro.
Independiente lost Fabian Vargas to a red card and three minutes later, and were hit on the break in stoppage time as Arsenal surged forward and substitute Dario Benedetto slotted in.
An own goal also put Argentinos Juniors on the way to a 2-1 win over Godoy Cruz, with Mauro Obolo sliding the ball in at the wrong end in the 23rd minute.
Leonel Nunez chipped a fine second goal from 20 yards 10 minutes later, before visitors Godoy Cruz netted a consolation through Diego Sevillano in the 87th minute.
Diego Ftacla scored a late equaliser for Tigre who drew 2-2 away to All Boys, ensuring both teams remain winless after four games.
Ivan Borghello put All Boys in front after 11 minutes, Martin Galmarini equalised in the 57th minute, and Mauro Matos restored the hosts' lead with 20 minutes to play.
Ftacla had the final say in stoppage time, drilling a powerful low shot inside the right post from 12 yards.