PSG saw its lead at the top of Ligue 1 reduced to three points on Sunday as Cedric Bakambu's goal in the 84th minute handed bottom-half side Sochaux a 3-2 home win against the French heavyweights.
The visitors snatched a 1-0 lead midway through the opening half as Javier Pastore's corner kick was nodded home by Alex.
Sebastien Roudet responded for Sochaux within seven minutes when he scored after a nice ball from Ryad Boudebouz to level the contest at 1-1 entering halftime.
Giovanni Sio put the hosts into the lead after the break when he hooked up with Roudet to fire a shot beyond the reach of PSG goalkeeper Salvatore Sirigu.
Sebastian Corchia nearly made it 3-1 as his free kick struck the post, only for PSG to haul themselves back to level terms in the 76th from another corner kick when a scramble in front of the net resulted in Sochaux's Jerome Roussillon redirecting the ball into his own net.
But the hosts still had a reply in the 84th minute with Sloan Privat knocking down a ball into the path of Bakumbu, who finished off the move with a precise shot.
The victory takes Sochaux three points above the relegation places, while PSG's lead now stands at three points over Lyon, which moved into second place with a dominant 4-0 win at Bordeaux.
Clement Grenier tallied a goal in each half for Lyon, while Gueida Fofana and Alexandre Lacazette also notched goals after halftime.
Sunday's other match saw Reims secure a 1-1 draw at home with St Etienne as Gaetan Courtet netted the equalizer for the hosts in the 76th minute to cancel out a first-half tally from St Etienne's Pierre-Emerick Aubameyang.