Mexico upset Germany 1-0 in their opening World Cup game, leaving the defending champions with a tougher task to qualify for the knockout stages.
In his World Cup debut, Hirving Lozano scored Mexico's winning goal in the 35th minute, picking up Javier Hernandez's pass inside the penalty area and dodging Mesut Ozil before firing past Manuel Neuer from 10 yards.
After Lozano's goal, Mexico goalkeeper Guillermo Ochoa pulled off a spectacular save to keep the score level, palming Toni Kroos' shot onto the crossbar.
Mexico pulled back into a more defensive formation midway through the second half as key players tired and had to withstand heavy pressure from Germany.
Germany is bidding to become the first team to retain the World Cup title since Brazil in 1962. It hadn't lost an opening game since 1982.
El Tri will take on South Korea and Germany faces Sweden Saturday in Group F play.