Costa Rica earned a shock 3-1 victory over favoured Uruguay, securing three points in their Group D clash on Saturday.
Los Ticos fell behind early, but battled back to leave Uruguay, who were playing without star man Luis Suarez, completely stunned.
Suarez, who has been battling for fitness, was ultimately an unused substitute.
Edinson Cavani put Uruguay ahead from the penalty spot in the 23rd minute.
Uruguay were awarded a penalty after Diego Lugano was hauled down in a not-so-subtle manner by Junior Diaz inside the penalty area.
Joel Campbell equalised for Costa Rica with a powerful shot in the 54th minute.
Oscar Duarte then gave Costa Rica a shock lead only three minutes later when he latched on to the end of a set piece.
Marco Urena added the finishing touches to a massive upset for Uruguay, with a fantastic finish in the 83rd minute.
It was his first international goal in three years.