Two goals from Oribe Peralta were enough to secure a deserved victory for El Tricolor and shock the highly-fancied Selecao who must settle for silver
Mano Menezes’ men had gone into the game as favourites to win their first ever Olympic title but were stunned early on as Mexico took a shock first-minute lead.
A mistake by Manchester United full-back Rafael allowed Oribe Peralta to drill home an early opener after just 28 seconds to leave the Selecao shell-shocked.
Brazil struggled to assert themselves in the game and indeed the best chances fell to Mexico particularly in the second half.
On the hour mark Brazil breathed a sigh of relief when Marco Fabian hit the crossbar, before Peralta had a goal ruled out for offside.
However, Luis Fernando Tena's men would not be denied and with a little over 15 minutes to go Peralta grabbed his second of the game with a superb header to give them breathing space.
A late strike from substitute Hulk reduced the deficit and Oscar had a glorious chance to equalise in the dying seconds but it was too little, too late as Mexico held on to seal the win and the gold medal.