River Plate suffered a surprise 2-0 defeat at home to All Boys which denied them the chance to move top of the Clausura standings.
The visitors took the lead after 36 minutes through Emanuel Gigliotti and a last-minute goal from Juan Rodriguez sealed the win.
River Plate sit two points behind leaders Velez Sarsfield and two ahead of Lanus, who held on for a goalless draw against Estudiantes despite the 65th-minute dismissal of Mario Regueiro.
Boca Juniors gave their campaign a welcome lift with a 2-0 victory at Argentinos Juniors. Martin Palermo grabbed the opener with just three minutes on the clock and Juan Riquelme doubled the lead after 20 minutes.
The win takes Boca up to 11th in the standings, with Independiente three places further down the table following a 1-1 draw against San Lorenzo.
Facundo Parra fired the home side in front in the 34th minute but Juan Salgueiro equalised for San Lorenzo four minutes after the interval.