Racing Club need just a point against Velez Sarsfield this weekend to secure second spot after earning a 1-0 victory against Atletico Rafaela.
Teofilo Gutierrez got the only goal from the penalty spot five minutes into the second half to keep Racing three points above Lanus, who also enjoyed a victory, winning 1-0 at Union Santa Fe.
Matias Fritzler got the goal after 15 minutes, and any hopes Union had of finding an equaliser were dealt a major blow when Jeronimo Barrales was sent off for a second bookable offence two minutes into the second half.
All Boys beat Argentinos Juniors 1-0 to leapfrog them in the table and move away from the danger zone.
Martin Zapata struck in the 13th minute and the visitors then had Nicolas Berardo sent off for a second booking 20 minutes from time.
Olimpo and Estudiantes shared the points from a 0-0 draw.
Boca Juniors had already wrapped up their first Argentine league title in three years with a 3-0 victory over Banfield on Sunday.
