David Trezeguet gave River Plate the lead after 12 minutes and Leonardo Ponzio doubled the advantage 11 minutes before half-time.
Emmanuel Gigliotti score a consolation goal for Colon with 15 minutes remaining.
Tigre lie fifth in the standings after beating mid-table San Lorenzo 1-0, Ruben Botta scoring the goal after 28 minutes.
Atletico Rafaela and Boca Juniors drew 1-1.
Juan Eluchans gave Atletico the lead with a 27th-minute penalty but Nicolas Blandi netted with seven minutes to go to ensure the game ended in a draw.