Argentina claimed a 1-0 victory over old enemies Brazil to help manager Jorge Sampaoli win in his first game as manager.
Sevilla defender Gabriel Mercado tapped in the only goal of the match on the stroke of halftime.
Brazil coach Tite will be left to rue the loss after the Selecao missed a number of chances to tie the game.
The 'Superclasico de las Americas' was officially labelled as a friendly, but that term was never going to be mentioned once the first whistle blew.
It was game on after only ten minutes when Paris Saint Germain star Angel Di Maria clattered into Manchester City midfielder Fernandinho. Somehow, the referee did not deem the challenge worthy of a booking.
The first chance of the game featured a clutter of Premier League stars.
Liverpool ace Philippe Coutinho opened Brazil's account after 22 minutes after being given the ball on a platter by Chelsea winger Willian.
Instead of taking an early shot, the midfielder decided he would try to go around Manchester United goalkeeper Sergio Romero but Manchester City defender Nicolas Otamendi scrambled back to block Coutinho's shot.
Despite having barely any chances in the first half, it was Argentina who would break the deadlock.
Otamendi headed a dangerous Angel Di Maria cross down past a diving Weverton. The header bounced off the post and across the face of goal, where Mercado was waiting.
The 30-year old couldn't miss as he tapped home from inside the six-yard box.
The second half was all Brazil, and the Selecao should of equalized with just under 30 minutes remaining.
Manchester City star Gabriel Jesus rounded Manchester rival Romero and an open goal loomed.
However, the 20-year star took a heavy touch and he is outstretched effort somehow hit the post.
The rebound then fell to Willian who managed to do the exact same thing.
The game died off in the closing stages as several substitutions were made by both teams.
Despite no points being on offer for the win, Sampaoli will view the victory as invaluable for an Argentina side that is languishing outside the World Cup qualification spots in South America.
For Brazil, their unbeaten run under Tite ends as they now look towards refining their squad for the 2018 World Cup with qualification already secured.
Brazil 0
Argentina 1 – Mercado 45'
Attendance: 95,569
Argentina Starting XI: Romero, Gomez, Mercado, Maidana, Otamendi, Di Maria, Banega, Biglia, Messi, Dybala, Higuain
Brazil Starting XI: Weverton, Fagner, Silva, Gil, Luis, Fernandinho, Augusto, Coutinho, Paulinho, Willian, Jesus.
