Victor Lopez scored the only goal as Newell's Old Boys beat River Plate 1-0 to re-establish their three-point cushion at the top of the Apertura table.
Newell's left it late with Lopez claiming the winner in the 77th minute, putting them three clear of second-placed Arsenal Sarandi.
Sebastian Abreu netted a last-minute equaliser to snatch a 1-1 draw for Rosario Central at Boca Juniors.
Boca would have gone third with a win and appeared to be on their way when Emanuel Gigliotti opened the scoring in the 13th minute but second-half substitute Abreu denied them.
Paulo Rosales scored a 28th-minute penalty and Ezequiel Cerutti netted a 34th-minute winner as Olimpo came from behind to win 2-1 at Velez Sarsfield, who had opened the scoring through Mauro Zarate (12).
And an own goal from Jose Gomez two minutes into the second half saw Estudiantes edge out winless Racing Club 1-0.
On Saturday it was: All Boys 0, Colon 0; Atletico Rafaela 1, Argentinos Juniors 0; Belgrano 0, Quilmes 1; Arsenal 2, San Lorenzo 1.