MEXICO CITY -- The semifinals of the Mexican Apertura swung into action on Thursday night, as Toluca and Leon both captured important victories in the first legs of their ties.

In the opening match of the round in Mexico City, regular season table topper Toluca pulled off a pragmatic 2-0 win over host America in front of a packed house at the Estadio Azteca. Despite an early offensive push from the host, the Red Devils defended bravely, and managed to score the opening goal in the 54th minute, as Lucas Silva headed home from close range off a Carlos Rodriguez pass.

Toluca looked set to take a minimum cushion into the second leg at home, but the visitors instead took advantage of a counter attack in the 90th minute to double their lead. Wilson Tiago found Paraguayan international Edgar Benitez, who beat America goalkeeper Moises Muñoz to provide the final scoreline.

The Eagles now have a significant challenge on their hands headed up the road to the Estadio Nemesio Diez for Sunday's rematch, given that Toluca has remained undefeated at home throughout the 2012 Apertura. Miguel Herrera's side, which must win by two and score at least three goals, may also be troubled by having failed to win in Toluca in its last eight tries in the "Bombonera."

The home team had better luck in the other Liga MX semifinal, as Leon pulled off a stirring 2-0 win over Club Tijuana in Guanajuato. The Panzas Verdes were the highest scoring side of the Apertura 2012, and they asserted their usual offensive thrust in front of an emotional home crowd, eventually breaking through in an otherwise relatively even contest.

Recently ascended Leon got the break through a strike from forward Othoniel Arce in the 55th minute, assisted by rapidly rising Mexican star Carlos Peña. The duo turned the tables two minutes later, with Arce assisting Peña to double the lead.

Despite a late push, Club Tijuana was unable to move the scoreboard, as Antonio Mohamed's team fell for the first time in 17 matches - it last lost on the second match date of the Apertura to the same Leon squad, also at Camp Nou.

The teams are now set for the return leg in Tijuana scheduled for Sunday evening, in which the Xolos will need a 2-0 win, or any other result in which the home side wins by three or more, to edge Leon for a finals spot in the battle of two relative newcomers to the deep stages of the Liga MX Liguilla.