Two goals in seven first-half minutes saw Belgrano Cordoba claim a 2-0 win at Newell's Old Boys in the Clausura.
Nestor Silvera opened the scoring in the 31st minute and Cesar Pereyra doubled the lead six minutes later. Newell's had their misery compounded when Hernan Pellerano was sent off four minutes from time.
In the day's other game, Hernan Lopez scored after 65 minutes, moments after stepping off the bench, to secure a 1-1 draw for Banfield against Godoy Cruz.
Alvaro Navarro had opened the scoring in the 12th minute for the visitors, who then had Leonardo Sigali sent off 17 minutes from the end.