Paris St Germain's Coupe de France final hangover continued as Ligue 1 rivals Montpellier came from behind with two late goals to win 3-2 at Stade de La Mosson.
The French champions were beaten in a penalty shoot-out by Rennes on Saturday, with forward Kylian Mbappe having been shown a red card for a studs-up challenge.
Thomas Tuchel's side, though, looked to have produced the required response on their return to league action, taking the lead following an own goal from Ambroise Oyongo in the 12th minute.
Montpellier, who needed victory to keep alive their own European qualification hopes, equalised when Presnel Kimpembe put the ball into his own net in the 21st minute – the defender having also scored an own goal in the cup final.
Angel Di Maria's clever finish just after the hour looked to have been enough for all three points.
However, with only 10 minutes left, Andy Delort equalised at 2-2, and there was still enough time for substitute Souleymane Camara to snatch a dramatic victory following poor PSG defending.
PSG came into Tuesday's game with a 16-point lead over second-placed Lille and the title already sewn up.
Tuchel was without suspended Mbappe as PSG made four changes, but Brazilian Neymar, who appeared to be involved in an altercation with a fan as he collected a runners-up medal, was in the side.
The Ligue 1 leaders broke the deadlock when Juan Bernat's cross was sliced past Montpellier goalkeeper Benjamin Lecomte by Oyongo.
It was, though, not long before the home side were level in the 21st minute following a free-kick.
Damien Le Tallec's close-range header looked to be dropping wide before Kimpembe deflected the ball past Gianluigi Buffon.
The veteran Italian soon had to make a couple of smart saves, first pushing over from Delort and then getting down to Ellyes Skhiri's low drive.
Montpellier threatened again after the restart when Florent Mollet took the ball down on his chest 25 yards out and sent a volley goalwards, which Buffon saved.
In the 62nd minute, Di Maria produced a neat finish after a ricochet off Marquinhos, spinning to round the goalkeeper and tap into an empty net.
PSG continued to press, with Julian Draxler's effort cleared off the line by Pedro Mendes.
At the other end, Delort fired over before midfielder Mollet tested Buffon with a low strike.
Montpellier's endeavour was rewarded with 10 minutes left.
A long throw from goalkeeper Lecomte was played on down the right by Mollet for Delort to run onto and into the box, before lifting the ball over Buffon.
Montpellier substitute Camara saw his header from a corner at the near post cleared off the line.
The comeback, though, was completed when defender Leandro Paredes was robbed of possession on the edge of the area after being given a quick pass by Buffon. Skhiri laid it off to Camara, who slotted the ball into the net.
In stoppage time, Colin Dagba saw his drive clawed away by goalkeeper Lecomte as Montpellier held out to secure a first victory over PSG since December 2016.
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