Paris Saint-Germain failed to bounce back from their Coupe de France final disappointment as they slipped to a 3-2 Ligue 1 defeat to Montpellier on Tuesday.

Thomas Tuchel's side threw away a two-goal lead to ultimately lose on penalties to Rennes on Saturday and never looked like returning to winning ways in a display characterised by woeful defending and scant attacking threat.

Ambroise Oyongo's own goal put them ahead after 12 minutes but Presnel Kimpembe – who endured a torrid game – put through his own net at the other end in the 21st minute to draw the hosts level.

Angel Di Maria had looked like securing just a second win in six games across all competitions for the Ligue 1 champions but, after missing a number of golden opportunities, Andy Delort showed superb composure in the 80th minute to draw Montpellier level.

Substitute Souleymane Camara then took advantage of a Leandro Paredes error to fire past Gianluigi Buffon five minutes from time to secure a famous win.

PSG forged ahead with their first meaningful attack of the game after 12 minutes, Oyongo thumping Juan Bernat's low cross into his own net from inside the six-yard area.

There was more slapstick defending at the other end nine minutes later as the hosts pulled level. Damien Le Tallec's header from Florent Mollet's free-kick was heading well wide but ended up creeping into Buffon's bottom-right corner courtesy of Kimpembe's hand.

The veteran PSG goalkeeper rolled back the years soon after, turning Delort's fierce drive over and then superbly tipping Le Tallec's whipped effort wide before the former blazed over from just six yards.

Tuchel's men looked sharper after the interval and retook the lead shortly after the hour mark. Di Maria audaciously pivoted around Benjamin Lecomte and fired into an empty net after Neymar had charged down Hilton's attempted clearance.

Pedro Mendes' superb clearance on the line denied Julian Draxler after 70 minutes before Delort set up a grandstand finish, latching onto Mollet's pass and clipping across a badly exposed Buffon.

Things were to get worse for PSG, though, when Paredes was caught in possession on the edge of his penalty area by Ellyes Skhiri, who teed up Camara to fire in from 12 yards and secure just Montpellier's second win in 18 league games against PSG.

What does it mean? PSG's season petering out in miserable fashion

It is hard to be critical of a team that has dominated Ligue 1 from the outset, but PSG's form has dropped off dramatically in recent weeks and they were again well below their high standards at Stade de la Mosson. Neymar – whose spat with a supporter after the Rennes defeat has dominated the headlines this week – played like it was a pre-season friendly and unfortunately for Tuchel, many of his team-mates were happy to follow his lead.

Montpellier, meanwhile, were outstanding and deserved the result. They move up to fifth, just five points behind fourth-place Saint-Etienne.

Delort keeps his head at the right time

The Montpellier striker was guilty of missing a number of wonderful opportunities but did not let that faze him when bearing down on Buffon for his side's second equaliser. He finished superbly past the goalkeeping great, laying the foundations for a dramatic late winner.

Kimpembe off the pace again

The young France international, who also scored an own goal against Rennes, has seen his form tail off badly in recent months and he put in another haphazard display. He gave away the free-kick that his own goal came from and was lucky not to be punished even further after a series of loose passes.

What's next?

PSG will hope to return to form when they host Nice at Parc des Princes on Saturday, while Montpellier welcome Amiens a day later.