Alianza Lima played to a 1-1 tie with San Martin, blowing a chance to catch up to Peruvian Clausura tournament leader Melgar.
Alianza Lima and Melgar's match on Wednesday had been rescheduled from a previous match day in the tournament, which wraps up over the weekend.
The match took place at Estadio Nacional in Lima.
Uruguayan-Peruvian Alejandro Hohberg scored for Alianza in the 65th minute and San Martin's Ake Loba, of the Ivory Coast, tied the score at 1-1 in the 75th minute.
Alianza has 27 points and is two back of first-place Melgar.
San Martin is in sixth place, with 21 points, and will have a hard time qualifying for the Copa Sudamericana, South America's secondary club competition.
On Sunday, Melgar faces San Martin, while Alianza goes up against Binacional.
Universitario de Deportes, which is fighting for a spot in the Copa Sudamericana, will play Comerciantes Unidos, which has been relegated to the Second Division.