Club America boosted their hopes of reaching the Liga MX final with a 1-0 win over Monterrey that put them in control of their Liguilla semifinal clash.
For the visitors, it was critical they grabbed an away goal, but it was Las Aguilas who started the more brightly, with Pablo Aguilar twice forcing Jonathan Orozco to a great save.
Monterrey grew into the game and came closest to grabbing a breakthrough when a Carlos Sanchez shot stung the palms of Club America goalkeeper Hugo Gonzalez.
Only minutes after the restart, Osvaldo Martinez fired in Andres Andrade's cross to give Las Aguilas the lead.
Monterrey were not going to leave the Azteca without a fight, though, and Edwin Cardona missed an excellent chance to level the score when he entered the center of the box and forced Hugo Gonzalez to a brilliant save.
Los Rayados grew in intensity when Antonio "Turco" Mohamed sent on Aldo de Nigris, who missed an incredible chance to equalize the score in the 83rd minute.
Club America withstood the pressure and even came close to doubling their lead. Dario Benedetto burst through the middle on a quick breakaway, but his decision making let him down as Paul Aguilar could only send his shot well wide.
At the final whistle, Las Aguilas earned an important result ahead of Saturday's second leg at the Estadio BBVA Bancomer, where Monterrey will have to score a goal to have any chance of progressing to the Liga MX final.