Leon stunned by Queretaro
Leon failed to keep the pressure on runaway Apertura leaders Club America following a 2-0 defeat at Queretaro.
The visitors could have closed the gap on the league's frontrunners to three points - albeit having played two more games - but they slipped further off the pace after their third loss of the season.
Wilberto Cosme opened the scoring on the half hour mark, while Esteban Paredes ensured there was no way back for Leon a minute after the interval.
To make matters worse for Leon, Santos Laguna moved up into second after holding off a late fightback from Monterrey to triumph 3-2.
Santos Laguna looked to be cruising to victory after scoring three times in 13 minutes through Oribe Peralta (49), Jesus Escoboza (59) and Mauro Cejas (62).
Despite substitute Humberto Suazo struck in the 83rd and 90th minutes to set up a tense finale, Santos Laguna managed to hold on.