The defending champions’ Ligue 1 title hopes were dealt a big blow on Sunday when they were held to a 1-1 draw at Stade Rennes, giving Lille a three-point lead at the top with two games remaining.
PSG finished with 10 men after Presnel Kimpembe was sent off in the 87th minute. Neymar opened the scoring with a penalty on the stroke of halftime, but Serhou Guirassy equalised in the 70th minute to leave PSG on 76 points.
Lille, who have 79 points after thrashing RC Lens 3-0 at home on Friday, will need four points from their final two games against mid-table St Etienne and Angers to secure their first Ligue 1 title since 2011.
Monaco is in third position with 74 points after beating Stade de Reims 1-0 away earlier on Sunday. Olympique Lyonnais is in fourth place with 74 points after defeating Lorient 4-1 on Saturday.
PSG, who were eliminated from the Champions League semi-finals by Manchester City on Tuesday, may find themselves without a big trophy at the end of the season.
On Wednesday, Mauricio Pochettino’s side will play Montpellier in the French Cup semi-finals.
“When you are PSG you have to do much better than that. Lille are very good, very strong. There are two matches left but we have to believe,” said PSG captain Marquinhos.
A minute’s silence was observed in honour of Christophe Revault, the former PSG and Rennes goalkeeper who died earlier this week at the age of 49.
PSG made an early challenge through Ander Herrera and Neymar, but Rennes countered quickly, with Jeremy Doku proving a nightmare for Layvin Kurzawa on the right flank.
After a VAR analysis, referee Ruddy Buquet awarded the visitors a penalty, despite the fact that it appeared Nayef Aguerd’s touch with Kurzawa occurred after the PSG fullback had fired over.
In the first half, Neymar converted a penalty kick six minutes into added time.
After the break, Doku, 18, started to cause problems for PSG’s defence, but Rennes’ goal came from a set piece, with Guirassy heading the ball into the top corner from Benjamin Bourigeaud’s corner.
PSG lost their cool once more, and centre back Presnel Kimpembe was sent off for a vicious challenge on Doku, leaving their defence exposed for the final minutes.
PSG, who are pursuing a fourth consecutive Ligue 1 win, needed a superb save from Keylor Navas to deny Flavien Tait in added time to salvage a point.