Cruz Azul clinched the league's best record after Puebla beat Monterrey by 2-0 on Sunday.
Instead, Puebla landed Monterrey a blow and with their 2-0 victor over Rayados ensured that Cruz Azul would finish atop the league. The result also clinched the second spot in the table for Monterrey.
With all hopes of claiming the top spot in the table gone, Monterrey manager Victor Manuel Vucetich was not unhappy with having had that vanish.
"We looked for it but it's not an objective," Vucetich said. "At the end of the day we know that in our league that does not give you much more other than a certain advantage in the return leg but it doesn't have much benefit. We're looking to reach the Liguilla well."
Perhaps he was indifferent about losing the chance to finish top of table because of last season. Monterrey finished with the most points in the league but were sent packing in the first round of the playoffs.
And when Monterrey won the league in the Apertura 2009 season, they did so by winning the first leg of each series, which were all at home.
Facing Puebla, Vucetich said his team did not respect Puebla as much as they should have.
"We were inconsistent," Vucetich said. "We came out a bit overconfident. I don't know if it was the difference in points between one team and the other played with us mentally."
Puebla's 29th-minute goal unsettled Monterey and made it a long match for the visitors.
"Once we found ourselves surprised, we wanted to react," Vucetich said. "All of the conditions were against us at that point. We were visitors and Puebla did what they needed to do."