PSG were thrashed 3-0 by AS Monaco in Ligue 1 on Sunday for their third defeat in five top-flight games.
Goals from Wissam Ben Yedder on either side of a Kevin Volland strike got the job done for the hosts, who were in inspired form on the night.
Mauricio Pochettino's side had more possession, completed more passes and had an equal number of shots in the match but couldn't find a way past the resolute Monegasques.
Ben Yedder opened the scoring in the 25th minute with a cheeky backheel shot after Youssouf Fofana found him unmarked in the center.
Volland then came off the bench in the second half to double their advantage, firing home a first-time shot off a cross from Ruben Aguilar.
He then won a penalty for Monaco in the dying stages after being hacked down by Presnel Kimpembe with Ben Yedder then stepping up to coolly convert from 12 yards.
PSG were absolutely woeful on the night, struggling to put up a fight despite dominating stats and not looking like a side contending for the title at all.
Their lead at the top of the Ligue 1 table could be cut to 12 points if Marseille win their clash with Nice later today.
While it's still a healthy advantage to have with only nine games remaining, pressure is mounting on the embattled Pochettino, who also oversaw a painful Champions League Round of 16 exit last week against Real Madrid.
Lionel Messi missed PSG's loss against Monaco
Lionel Messi was absent from the clash with the flu.
He's come under fire for disappointing performances with PSG, with many even blaming him for their poor results.
But even without him today, the French giants struggled, and now, the fans are asking who's to blame for the loss.
Neither Kylian Mbappe nor Neymar could rescue the Parisians from this debacle.
With Di Maria also injured, Pochettino went with Giorginio Wijnaldum on the right wing, a tactical move that backfired spectacularly as the Dutchman struggled big time.
Here are some of the best reactions from the match: