Newell's Old Boys withstood the early dismissal of Victor Lopez to beat struggling San Martin de San Juan 2-0 in the Argentine Apertura.
Marcos Caceres gave Newell's a 14th-minute lead with a close-range header but Lopez was sent off for a two-footed lunge on Leandro Velazquez seven minutes later.
Substitute Nacho Scocco, who had been on the pitch only three minutes, finished off the visitors in the 72nd minute with a second strike for Newell's, a classy 25-yard strike into the top left corner.
Racing are one of five clubs with seven points from three rounds of games, with Quilmes also in the quintet.
Quilmes were 2-1 winners at home against Union Santa Fe, with Pablo Lima and Joel Carli on target.
Lima arced home a free-kick, left-footed into the right corner, from 35 yards for a superb opener in the 32nd minute, before Juan Avendano poached an equaliser from much closer range three minutes later.
Carli had the final say, in the 83rd minute, when his firm downward header bounced once on its way into the right corner of Alejandro Limia's goal.
Arsenal Sarandi were held 2-2 at home by Argentinos Juniors, who registered their first point.
Lisandro Lopez and substitute Dario Benedetto scored for Arsenal de Sarandi, after 13 and 74 minutes, with Diego Placente (52) and an own goal from Diego Braghieri (72) registering for Argentinos Juniors.
