Guillermo Rojas scored in the 47th minute and short-handed Atlante beat Estudiantes Tecos 2-1 in Group A play of the Interliga tournament on Saturday night.
Atlante played one man down in the second half after defenseman Jose Daniel Guerrero was sent off late in the first for tripping Tecos midfielder Rubens Oscar Sambueza.
But Atlante took the lead for good two minutes into the second half, when Christian Bermudez threaded a short cross to a sprinting Rojas for an easy goal past goalkeeper Mario Rodriguez.
The InterLiga tournament is an annual eight-team event between Mexican clubs to determine the two that will play in the Copa Libertadores, the South American club championship.
Tecos missed a point-blank chance to tie it a few minutes after Rojas' goal. But Fredy Bareiro's header hit off the left post and Mauro Cejas' rebound shot caromed off the crossbar.
Atlante held on despite Tecos' 15-9 advantage in shots.
Daniel Arreola put Atlante ahead in the 10th minute, launching a left-footed shot from 30 yards that sailed over Rodriguez.
Tecos tied it in the 29th minute, when Cejas drove home a short, left-footed pass from Bareiro.
Atlante won for the first time in its seven Interliga games. Tecos is playing in the Interliga for the third time in four years.
Club America faced Santos later Saturday. The four teams will play again on Tuesday.