Tijuana beats Toluca 2-1 in final first leg
Replays showed Aguilar was slightly offside, sparking protests from Toluca players and manager Enrique Meza at halftime.
Tijuana had the better of the possession and play in the second half, but the game became largely a midfield battle and was a much tighter affair.
Over the 90 minutes, Tijuana had eight shots on target compared to Toluca's two.
Toluca went into the final as slight favorite and finished as leaders in the regular-season standings, but a draw in the second leg is good enough to see Tijuana crowned champion.
"We are happy, we fought to the end like always," Tijuana's Colombian striker Duvier Riascos said. "The team gave its all to get an important result and thanks to God we achieved it."
With only a one-goal deficit to overcome, Benitez said his side can snatch the title in the second leg, saying: "We've got to be calm, look for the goal and to control the game."
The Mexican season is divided into two halves — the Apertura season — the one now underway — and the Clausura season starting in January. Each crowns its own champion.