Brazil's Botafogo withstood waves of attacks from Paris St Germain to stun the European champions 1-0 on Thursday and throw Group B at the Club World Cup wide open.
PSG dominated possession at the Rose Bowl in Pasadena but Botafogo's resolute defense stood tall in the first competitive meeting between the two clubs, Reuters reported.
The goal came in the 36th minute when Botafogo gained possession in midfield and Jefferson Savarino slid a pass through for Igor Jesus to run in on goal.
Jesus outmaneuvered two defenders and his shot deflected off the leg of PSG's Willian Pacho, the ball changing direction and leaving goalkeeper Gianluigi Donnarumma flatfooted and only able to watch as the ball skipped into the net.
Jesus celebrated by hopping over the barrier and was mobbed by delirious Botafogo fans.
PSG continued to be the aggressors in the second half as Botafogo were content to protect their lead and try to capitalize on the break.
PSG, who had scored 19 goals in their last five matches, had the ball in the net in the 79th minute but the goal was chalked off for offside and Botafogo held for the shock win.
The Brazilians became the first team to stop PSG scoring since March when Liverpool defeated them 1-0 in the Champions League. The French side had scored in 19 consecutive games until losing on Thursday.
Botafogo coach Renato Paiva said his team had beaten PSG at their own game.
"Being a great team, playing together, all the guys defending, all the guys attacking, and that's the big secret of this PSG team, that's why they compete and win," he said.
"They are a fantastic team. I said this, PSG are a lesson to everybody nowadays in football. And I told my guys, just be a team, enjoy playing together, attack together, defend together, and enjoy. And they did they did it. Fantastic."
PSG were once again without Ousmane Dembele, who suffered an injury while playing for France in the UEFA Nations League earlier this month.
The victory gives the South American champions a huge boost in their hopes of advancing to the knockout rounds after they beat MLS side Seattle Sounders 2-1 in their opener.
PSG, who thrashed Atletico Madrid 4-0 in their first match, will look to bounce back against the Sounders on Monday while Botafogo are back at the Rose Bowl again to take on Atletico the same day.
Brazil's four teams at the 32-club tournament are unbeaten so far and Paiva said it showed the strength of the game in the South American nation.
"I think it's the quality of Brazilian players, the quality of what people are doing in Brazil, especially the coaches," he said.
"Brazil will always be Brazil in world football."
