All Boys climbed up to third spot in the Clausura standings with a 1-0 home win over lowly San Martin San Juan.
Mauro Matos' 18th-minute strike after a poor kick from goalkeeper Luciano Pocrnjic proved the difference in a match which saw both sides reduced to 10 men.
Visiting defender Emanuel Mas received his marching orders in the 42nd minute before All Boys lost Carlos Soto in the 65th minute.
The victory lifts All Boys to within a point of joint leaders Tigre and Newell's Old Boys.
Estudiantes moved into the top six with a 3-0 triumph at Banfield. The goals came from Matias Sarulyte, Duvan Zapata and Gaston Fernandez.
In the day's other game, Francisco Barisone scored three minutes from time to give Union Santa Fe a 1-0 win over San Lorenzo.