Newell's Old Boys went top of the Argentinian Apertura with a 2-1 win away to Colon Santa Fe.
Nacho Scocco gave Newell's the lead after 13 minutes and Marcos Caceres extended the advantage just after the hour.
Lucas Mugni scored what turned out to be a consolation for Colon with 18 minutes to go.
Boca Juniors missed their own chance to go top as a 2-0 defeat to 10-man Lanus kept them in third place.
Mario Regueiro opened the scoring for Lanus after 33 minutes but was then sent off with seven minutes to go.
Five minutes later Diego Valeri secured the three points for 10-man Lanus who moved up to mid-table with the win.
Gaston Caprari, Humberto Osorio, Jorge Luna and Sebastian Penco scored for San Martin San Juan in the 4-0 defeat of Quilmes.
Racing Club won 1-0 away to River Plate with Matias Cahais getting the only goal after 71 minutes.