Tigre won 1-0 at Velez Sarsfield to steal a march in the Clausura title race and end the hopes of their hosts.
Carlos Luna's strike in the 79th minute put Tigre top of the table, two points ahead of Boca Juniors and three in front of Arsenal Sarandi, who play each other on Sunday.
Velez, who had Fabian Cubero sent off in the 68th minute, were left five points off the top, one point behind Newell's Old Boys, who are also now out of the race.
Belgrano Cordoba recovered from going behind in the first minute to beat Banfield 3-1. Diego De Souza Carballo opened the scoring within moments of kick-off, but Frederico Almerares levelled five minutes before the break, and half-time substitute Lucas Melano bagged a quickfire double midway through the second period.
The day's other game saw Estudiantes beat Olimpo 1-0 with a 51st-minute goal from Gabriel Mercado.
The day's results mean Atletico Rafaela will be relegated along with Olimpo, while Banfield and San Lorenzo occupy the promotion-relegation play-off places.
Above them in the table that decides relegation, which is worked out over three seasons, are San Martin San Juan and Clausura leaders Tigre.