First-half goals from Matias Britos and Nelson Maz propelled Leon to a 2-0 win over Tigres on Saturday that moves the club to within four points of Apertura leaders Tijuana.
A six-point gap separated Tijuana from Leon at the start of the weekend, but Leon's win coupled with a 2-2 draw for Tijuana at Santos sees the advantage shrink to four points.
Britos got Leon off to a flying start by scoring in the opening minute, while Maz doubled the lead from the penalty spot in the 36th.
Tigres has lost its last three games and sits in the bottom half of the league table.
Tijuana overcame an early goal from Daniel Luduena of Santos with two of its own to take a 2-1 lead into the final 20 minutes. However, Luduena scored again in the 74th minute to help Santos grab a share of the points.
Cruz Azul downed Queretaro, 3-2, with two goals from Omar Bravo, while the other match on Saturday saw Jeronimo Cevallos score twice in the final eight minutes to help Atlante earn a 2-2 draw at San Luis.
On Sunday, UNAM moved into the top four by beating Pachuca, 1-0, with a goal from David Ramirez in the 84th minute, and Guadalajara was held to a 1-1 draw at home by Jaguares as the visitors scored in the equalizer in the 67th minute through Luis Rey.