In the 12th minute, Chivas defender Carlos Salcedo gifted Portugal the lead when Diego Jota took advantage of a bad pass to beat Raul Gudiño.
The advantage was extended from a corner when Ruben Neves scored the 2-0 with a header, after the ball had bounced off the post.
In the second half, a mistake from Jonathan Espericueta finished with Iuri Medeiros putting Gelson Martins through for the 3-0.
Arturo "Poncho" Gonzalez could have pulled one back but was denied from a one-on-one.
Finally, in the closing stages of the game, Antonio Briseño conceded a penalty on Gelson Martins. Ricardo Horta stepped up and slotted to the right of Gudiño, who went the other way, to seal a resounding victory for the hosts.
Mexico is set to defend their Olympic gold medal title in this summer's Olympic games.
You can watch highlights of Mexico's defeat below: