Tijuana and Toluca have the upper hand in their respective Mexican Apertura quarter-finals against Monterrey and Guadalajara respectively.
Gregory Garza Early struck late as Tijuana snatched the initiative against Monterrey.
Substitute Garza Early popped up with the only goal in the 86th minute as Tijuana takes a 1-0 lead into the second leg at home.
There was also an away win for Toluca, which beat Guadalajara 2-1.
The visitor took control of the match midway through the first half as Antonio Rios opened the scoring in the 24th minute and Antonio Naelson added a second moments later.
Rafael Marquez Lugo's 74th minute penalty gave Guadalajara a way back into it, but it has plenty of work ahead of it in the second leg.