The hosts took the lead against the run of play on 16 minutes when Luiz Gustavo was afforded time and space to line up a strike from distance on his left foot.
Gustavo's powerful shot swerved away from PSG goalkeeper Alphonse Areola to find the bottom corner of the net, sending the home crowd wild.
Although the Brazilian scuffed his left-footed attempt, the ball struck the inside of the post and nestled into the bottom corner beyond the grasp of Steve Mandanda.
PSG looked to be heading for defeat when they went down to 10 men due to Neymar's sending-off for a second yellow card in the 87th minute following a spat with Lucas Ocampos, though replays showed that no contact was made.
However, a free kick given away by Bouna Sarr in injury time gave Edinson Cavani the chance to draw level from 25 yards, and the Uruguayan made no mistake by curling the ball over the wall and striking the underside of the bar before bouncing over the line.