MEXICO CITY (AP) -- Tigres, Morelia and Santos Laguna improved to 14 points to share the Mexican first-division lead through seven rounds.
Tigres, which leads the other two on goal difference, drew 0-0 against Atlas. Morelia defeated Puebla 2-1, and Santos Laguna drew 1-1 against Monterrey.
Pachuca missed an opportunity to move into first place and lost its unbeaten record on Sunday, falling 1-0 against America to stay on 12 points.
Chivas' poor play continued with a 0-0 draw at home against San Luis. Chivas is one of Mexico's most popular clubs but has only two points in seven matches.
In other weekend results: Cruz Azul and Pumas drew 1-1, Estudiantes defeated Atlante 2-1, Toluca defeated Jaguares 3-1, and Queretaro lost 2-0 against Club Tijuana.