One of the favorites to win the title, Guadalajara Chivas, stumbled to a 1-0 loss against Atlante on the opening weekend of Mexico's Clausura season.
Defending champions Tigres also got off a slow start with a 1-1 draw against Cruz Azul.
In other results, last season's runner-up Santos drew 0-0 against Pachuca, America defeated Queretaro 2-0, and Toluca defeated Estudiantes Tecos 3-1. Also, Monterrey won 2-1 against Jaguares, Morelia and Tijuana drew 1-1, San Luis defeated Pumas 1-0, and Puebla drew 0-0 against Atlas.
Chivas went behind a minute before halftime on a goal from Michael Arroyo of Ecuador. Peruvian forward Andres Mendoza drove into the penalty area and squared the ball to Arroyo, who tapped into an empty net to give Atlante the victory.
Tigres' visit to Cruz Azul began with Tigres midfielder Carlos Salcido getting hit on the head with a bottle as he was getting off the team bus in Mexico City. Salcido wasn't seriously injured and played the full game.
On the field, a sixth-minute goal by Christian Gimenez put Cruz Azul into the lead, with Tigres captain Lucas Lobos equalizing in the 70th.
Both Santos and Pachuca had good opportunities to score, but failed to convert.
Cesar Ibanez was sent off for Santos in the 89th minute after receiving his second yellow card.
Ecuador striker Christian Benitez had a penalty saved in the 27th, but opened the scoring for America against Queretaro in the 69th when he was sent clear on goal by a defense-splitting pass from Matias Vuoso. Juan Carlos Medina added America's second in injury time.
Toluca defeated relegation-threatened Estudiantes Tecos, with all the goals coming in the second half. Chilean striker Ivan Alonso, the league's top goalscorer last season, started the new season by scoring two goals for Toluca, with Edgar Duenas getting the team's third. Fredy Bareiro got a consolation goal for Estudiantes Tecos.
Two second-half goals in the space of three minutes from Walter Ayovi put Monterrey two ahead against Jaguares, who got a goal back through Jackson Martinez in the 80th.
Morelia took the lead in the 23rd minute with a goal by Rafael Marquez. Argentine Jose Sand equalized for Tijuana from the penalty spot in the 47th after Colombian striker Duvier Riascos had been brought down.
San Luis went down to 10 men in the 34th when Argentine Anibal Matellan was sent off, but a dipping volley from 25 meters (yards) by Jehu Chiapas in the 41st gave San Luis the victory against Pumas.
Puebla couldn't break down 10-man Atlas in the second half after Lucas Ayala was sent off just before halftime for swinging his arm in anger. Rodrigo Salinas came close for Puebla in the 83rd when he drove a right-footed shot from outside the area, but the ball struck the crossbar.
