Mexico made a commanding start to the defence of their Gold Cup crown as Javier Hernandez hit a hat-trick in a 5-0 win over El Salvador in Texas.
The 2009 champions breezed to victory against their Central American neighbours with Manchester United striker Hernandez scoring his side's last three in the 60th, 67th and 95th minutes, the latter being a penalty deep into added time.
Efrain Juarez and Aldo de Negris had set up the win with the two opening goals.
Also in Group A's opening fixtures, Costa Rica enjoyed a similarly emphatic start with victory over their Caribbean neighbours Cuba, winning 5-0 at the Cowboys Stadium.
Marcos Urena opened the scoring within seven minutes with goals following from Alvaro Saborio. Urena added his second of the night early in the second half before Heiner Mora scored a minute later and Joel Campbell wrapped up the win.