Alexis Castro and Santiago Ascacibar scored either side of halftime as Estudiantes eased to a 2-0 win at River Plate in Argentina's Primera Division Apertura tournament on Saturday.

Castro gave his side the lead in the ninth minute by tapping home from close range following Tiago Palacios' cross from the right side of the penalty area.

The host was reduced to 10 men just before the hour when Enzo Perez was shown a straight red card for a bad tackle on Cristian Medina.

Ascacibar put the result beyond doubt in the 94th minute with a first-time effort from the edge of the six-yard box after Edwuin Cetre's angled shot was parried away by goalkeeper Franco Armani.

The result leaves Estudiantes top of the 15-team Group A standings with 18 points from eight outings, while River Plate is third in Group B with 15 points.

Earlier on Saturday, Sarmiento recovered from a two-goal deficit to salvage a 2-2 draw at Aldosivi in Mar del Plata.

Sarmiento is 12th in Group B with six points, while Aldosivi is last in Group A with just two points so far.