Arsenal Sarandi have clinched the Clausura crown - their first Argentinian title - after beating nine-man Belgrano 1-0 in a stormy encounter.
The hosts, who started the day level on points with Tigre, took the lead after 28 minutes through Lisandro Lopez, with Belgrano's response limited due to the dismissals of Luciano Lollo and Claudio Perez.
Tigre could only manage a 2-2 draw at home to Independiente.
Carlos Luna put the hosts ahead after 21 minutes but a double from Patricio Rodriguez swung the game in Independiente's favour. The sending-off of the visitors' Osmar Ferreyra offered Tigre hope but they could only muster an equaliser via a Diego Morales penalty.
Boca Juniors, who this week advanced to the final of the Copa Libertadores, slipped to fourth following a 3-1 defeat at All Boys - Emanuel Perea netting a hat-trick - and were replaced by Velez Sarsfield, 2-1 winners at Racing last night.
Atletico Rafaela won 3-1 at Godoy Cruz to climb out of the relegation play-off. Fabricio Fontanini, Sebastian Carrera and Alexis Castro scored the goals after Ruben Ramirez's early penalty for Godoy.
Estudiantes beat Union Sante Fe 2-1 while Banfield's game at home to Santa Fe was abandoned after 83 minutes due to crowd trouble. Sante Fe were leading 3-0 at the time, a result which, if confirmed, would condemn Banfield to relegation.
San Lorenzo temporarily avoided the drop after beating San Martin San Juan 3-1 with two goals from Carlos Bueno. Both clubs will now play a promotion/relegation play-off.