Luis Madrigal scored twice in the span of seven minutes as Monterrey claimed a 3-1 away victory against Morelia, which dropped into third place, two points adrift of the leaders.
Madrigal found the breakthrough in the 49th minute to put Monterrey in front, and he doubled his tally in the 56th.
Aldo Ramirez halved the deficit for Morelia with a goal in the 67th, but any hope of claiming something from the contest was dashed as Monterrey added a third goal 13 minutes from time through Alejandro Ruiz.
The win is just the third of the season for Monterrey in 11 attempts, while Morelia lost for the third time.
Both America and Leon took advantage of Morelia's defeat by winning their respective matches over the weekend to move to the top.
America secured a 3-1 home win over Jaguares with goals from Rubens Sambueza, Miguel Layun and Raul Jimenez, while Hernan Burbano and Luis Montes were on target for Leon in a 2-1 triumph against Guadalajara.
Leon and America are level on 22 points, but America still has two games in hand.
Fourth-place Queretaro sustained a 4-0 defeat at Toluca, which got two goals from Raul Lopez to move to within a point of its opposition, while Santos needed a goal from Eduardo Aguirre in stoppage time to earn a 1-1 draw at Pachuca.
Atlante downed UNAM, 1-0, despite playing the final 30 minutes with 10 men, Tigres and Puebla played out a 0-0 draw, Edson Rivera scored five minutes into stoppage time to earn Atlas a 3-3 draw with Veracruz, and Tijuana battled Cruz Azul to a 0-0 stalemate.