Velez Sarsfield stretched their lead at the top of the Argentinian Apertura to eight points over Newell's Old Boys with a 3-0 win over 10-man San Martin San Juan on Monday.
Velez opened the scoring through Fabian Cubero after 22 minutes and Federico Insua extended their lead three minutes later.
To make matters worse for the visitors they had Reinaldo Alderete sent off five minutes before half-time.
Ezequiel Rescaldani wrapped up the scoring after 63 minutes to leave San Martin San Juan in the bottom three in the table.
Juan Ramon Riquelme returned as captain of Boca Juniors Sunday but couldn't make the difference as Union Santa Fe, without a win in 26 league games, recorded a shock 3-1 victory at the Bombonera.
City rivals River Plate lost 2-0 against San Lorenzo, also Sunday, as Lanus held onto the lead in Argentina's first division after a 0-0 draw with Racing.
In other Sunday games in Argentina, Godoy Cruz drew 0-0 with Argentinos Juniors and Tigre defeated All Boys 2-1.
Riquelme made little impact in his comeback after eight months of retirement and Damian Lizio put Union ahead against Boca in the 26th minute, chipping the ball over goalkeeper Agustin Orion from the edge of the six-yard area.
Bruno Bianchi doubled Union's lead with a strike from inside the penalty area in the 34th minute and Pablo Magnin added a third in the 51st minute by turning in the rebound after Andres Franzoia struck the post.
Uruguayan forward Santiago Silva headed home to claim a consolation goal for Boca in the 89th minute.
River Plate had won all three of its games under returning manager Ramon Diaz, but fell behind against San Lorenzo after 41 seconds when Denis Stracqualursi rifled in a shot following a scramble in the penalty area.
Mauro Cetto headed in San Lorenzo's second in the 20th minute to wrap up the scoring.
Lanus' perfect start to the season also came to an end but the team has yet to concede in four games and the goalless draw with Racing left it one point above River Plate.
Argentinos Juniors held on to the draw against Godoy Cruz despite ending the game with nine men, after Lucas Rodriguez was sent off in the 73rd and Anibal Matellan followed in the 84th.
Matias Perez scored in the 7th and the 30th for Tigres, with Santiago Montoya getting All Boys' goal in the 10th.
In Saturday games, Colon's Facundo Curuchet and Hernan Bernardello each scored in the last ten minutes to rescue a point in a 3-3 draw against Estudiantes.
Estudiantes went into the lead in the 4th through Maximiliano Nunez and doubled it in the 12th via Roman Martinez.
Duvan Zapata again gave Estudiantes a two-goal advantage when he scored a penalty in the 62nd, after Emanuel Gigliotti had pulled one back in the 24th.
Lisandro Lopez struck just before halftime in Arsenal's 1-0 victory over Independiente.
On Friday, Quilmes drew 3-3 with Rafaela with all six goals coming in the second half, while Newell's defeated Belgrano 2-0 thanks to goals from Ignacio Scocco and Maximiliano Urruti.
In Monday's game, Velez Sarsfield take on San Martin.
