San Lorenzo moved within a point of league-leading Newell's Old Boys with a 2-0 victory Colon in the Argentine league.
Ignacio Piatti and Juan Ignacio Cavallaro scored second-half goals to improve San Lorenzo to 16 points in eight matches, one behind Newell's. Arsenal and Gimnasia are three points off the lead.
Newell's retained its league lead with a 1-0 victory over lowly Racing Club on Friday.
River Plate defeated All Boys 1-0 on Sunday to improve to 11 points, getting the winning goal from Carlos Carbonero in the 80th minute.
In other matches Sunday, Quilmes drew 0-0 against Lanus, Estudiantes and Gimnasia drew 1-1 and Boca Juniors played a scoreless draw with Argentinos Juniors.