More than 3,000 players, some as young as 10 and others into their 20s, are competing this weekend.
The tournament is a big deal. Scouts are looking for players for Mexico's national teams that will face off in the next World Cup in Denmark.
"For us it's the best tournament in all the country so we have been training a lot for this tournament," says Coach Pedro Ramirez. "We have big expectations for the girls to play here and (gain) knowledge."
Football's popularity growing among girls in Mexico
Flag football player Carla Castro says girls in Mexico are expected to dance ballet or jazz, or play soccer. "And now girls are like getting more into sports that were created for boys."
The NFL's popularity in Mexico is second only to in the United States.
Sylvia Torrez says while soccer is still the main sport in Mexico, they've learned to love American football.
"This is much more passionate. It's more dynamic definitely. Instead of soccer, one person has the ball, they think about it, here it's like back and forth with defense, offense, more exciting definitely."
The Chargers are taking on the Kansas City Chiefs on Monday Night Football in Mexico City, and you can watch the game on ABC7. Coverage begins with a 4:30 p.m. PT pre-game show. Jovana Lara and Curt Sandoval will be bringing you stories live from Mexico. Watch for their live reports on Eyewitness News.