Paris Saint-Germain’s star duo, Neymar and Kylian Mbappe, fired blanks as Monack thrashed the giants 3-0 in a Ligue 1 encounter on Sunday.
The Parisiens were without Lionel Messi as the Argentine was down with flu.
The champions remain 15 points clear of second-placed Marseille at the top of Ligue 1 after the fourth league defeat of the season for Mauricio Pochettino’s men, who have been shaken since being dumped out of the Champions League by Real Madrid.
Nice can close the gap to 12 points if they beat Marseille in Sunday’s late Ligue 1 game.
Monaco captain Ben Yedder is now Ligue 1’s top scorer with 18 goals after his 25th-minute tap-in from a rebound, and an 84th-minute penalty.
Ben Yedder also helped in the build-up for German striker Kevin Volland’s goal for Monaco, making it 2-0 on 68 minutes in what was the real turning point of the game as PSG began to chase.
Mbappe said the bitterness of the Champions League defeat earlier this month was still felt at the club.
“We could win 8-0 and nobody would care, they’d just be thinking about the Champions League,” he said.
“We need to remain professional, think of our families.
“They are a great team, playing in European competition.”
Monaco’s Belgian coach Philippe Clement can also thank his goalkeeper Alexander Nuebel, who made important saves from Mbappe, Neymar and the marauding Moroccan Achraf Hakimi.