28-year-old Dembele, who added the FIFA Best award to his Ballon d'Or earlier this week, netted from the spot in a game played at Nantes' Stade de la Beaujoire.

PSG are bidding for a third consecutive French league and cup double this season but sit second in Ligue 1, one point behind surprise leaders Lens.

Dembele set up Desire Doue to open the scoring in the 25th minute with a cool, low finish into the far corner.

PSG were awarded a penalty shortly afterwards for a shirt pull on Goncalo Ramos and Dembele stepped up to score for the first time since October, ending a run of eight appearances without a goal.

It was only the France forward's fourth goal of an injury-disrupted season.

"It's important to get playing time, especially for players returning from injury. He had a good game and played 60 minutes," said PSG coach Luis Enrique.

Ramos made it three in the 53rd minute, tapping in Senny Mayulu's low cross after a swift team move, before doubling his tally just five minutes later.

Elsewhere, Lille needed an 80th-minute goal from Marius Broholm to get past fourth-division Creteil 1-0, while Lorient saw off AS Le Gosier of Guadeloupe 7-0 in a game played in a Paris suburb.