Carlos Ruiz scored two goals to help Puebla beat Tigres UANL 4-1 in the Interliga on Sunday.
In the later game, apertura champion Monterrey and Jaguares de Chiapas had a scoreless tie. Monterrey had 12 shots, but Jaguares hit the goalposts twice.
Alavaro Gonzalez also scored two goals for Puebla, which was making its InterLiga debut.
The eight-team tournament of top Mexican club teams, will determine two spots in the Copa Libertadores, South America's professional championship.
Ruiz scored 31 goals in 68 MLS games with FC Dallas.
"I still think of this as my home," Ruiz said. "My family lives here and for me, it was great to see my family in the stands and watch me play. Maybe one day I can come back here and play again for FC Dallas."
Gonzalez, who left the match in the 53rd minute with a broken nose following a violent collision, scored goals 13 minutes apart in the first half to give Puebla a 2-1 lead after Tigres jumped on top early.
"The two forwards, we each scored two goals, so that's good," Ruiz said. "I think we play a great teamwork, and for the forwards to score two goals, that's great for us."
Tigres, the only team to have won the InterLiga twice, struck first through Itamar Batista, but Puebla responded eight minutes later.
"We are not used to what happened to us today," Tigres coach Daniel Guzman said. "I was surprised that the other team was able to take advantage of all of our errors but we will improve for the next game. We're very clear about what we need to do."
The temperature reached 37 degrees, with a much colder wind chill.
"It made it complicated, it was very cold," Jaguares defender Edgar Andrade said. "But we have to get used to it quickly."
Monterrey's Sergio Santana had three opportunities, drilling shots just over the crossbar in the 51st and 57th minutes. Later he had a header from five yards out that bounced just wide of the right post.
William Parades also had a dangerous shot from 25 yards out in the 52nd minute, but Jaguares goalkeeper Oscar Perez dove to knock it away.
"In general terms, Im happy because all our players worked hard to play good soccer," Monterrey coach Victor Manuel Vucetich said. "But Im not happy with the score of the game because we had scoring opportunities that we couldnt finish."