Estudiantes made it two wins out of two in the Argentinian Clausura with a 1-0 success at 10-man Quilmes on Sunday.
The hosts had Enzo Kalinski sent off in 32nd minute and Estudiantes took advantage, Gabriel Mercado's effort on the stroke of half-time proving enough to secure victory.
The win moved Estudiantes level on six points with Olimpo at the top of the table.
In the day's other game, two second-half goals earned River Plate a 2-0 win at home to Huracan.
Eric Lamela opened the scoring in the 50th minute and Paulo Ferrari made the points safe nine minutes later.
