The USMNT beat rivals Mexico in a fiery friendly that saw Mateo Chavez shown a red card for slapping Sebastian Berhalter in the face.Mauricio Pochettino’s team secured a 3-0 win over their neighbors in Glendale, Arizona, on Saturday night, with teenage sensation Cavan Sullivan becoming the youngest goalscorer in USMNT history.But the game descended into chaos midway through the second half, after Chavez fouled Yunus Musah. Berhalter confronted and shoved Chavez, prompting the Mexico star to slap his rival with both hands.The USA midfielder, son of former coach Gregg Berhalter, hit the floor before Chavez was shown a straight red card. The Mexico defender had been on the field for barely 20 minutes and his sending off sparked a scuffle between the two sets of players, with Pochettino and other members of his staff having to run on to separate the teams.It marked only the latest instance of chaos in games between Mexico and the United States in recent years. Mexico star Mateo Chavez was shown a red card for slapping Sebastian Berhalter in the face Following the red card, a scuffle broke out between the two teams at State Farm Stadium Mauricio Pochettino and members of his staff rushed on to the field to separate the teamsJust minutes before the red card, 17-year-old Sullivan profited on a catastrophic error by Mexico goalkeeper Raul Rangel to give the USMNT a 2-0 lead.Sullivan intercepted a pass from Rangel before brilliantly lifting the ball past the goalkeeper from well outside the box. That goal came either side of strikes from 18-year-old Julian Hall and Malik Tillman.Pochettino’s team is rebuilding after suffering World Cup heartbreak on home soil and victory over Mexico was their third win in three games during this international window.The US has also beaten Peru and Chile, with the latter featuring its own share of carnage after a bench-clearing brawl broke out at the end of the game. Pochettino’s team take on Canada on Tuesday.