Defending champion Monterrey took a 3-1 lead over UNAM Pumas after the first leg of their Mexican Clausura playoff quarter-finals Thursday.
Osvaldo Martinez opened the scoring in the 11th minute, Walter Ayovi hit a long-range second ten minutes later and Humberto Suazo tapped home a third three minutes after half-time.
Martin Bravo pulled a goal back with 20 minutes remaining to give Pumas a glimmer of hope ahead of the return leg in Mexico City on Sunday.
Club America was beaten 2-1 at home by Morelia in the first match of its quarter-final.
Manuel Perez gave the visitor a 17th-minute lead which Marquez Lugo extended after 61 minutes.
Substitute Daniel Marquez got America on the scoresheet nine minutes later,
just three minutes after coming off the bench, but it was unable to add to
its tally and now faces a tricky return leg in Morelia.
In other first leg results from Wednesday, Guadalajara had a 3-1 win against Tigres and Cruz Azul downed Atlante 2-1. Those ties finish Saturday.
