Runaway leaders Paris Saint-Germain have opened a 10-point lead at the top of the French league standings before the year-end break with a 4-2 defeat of Monaco in a match marred by Gianluigi Donnarumma's injury.

Ousmane Dembele scored a brace and striker Goncalo Ramos put PSG back in the lead with seven minutes left as he headed in a corner after coming in as a substitute in the lively encounter at the Stade Louis II on Wednesday.

Monaco remain in third place, level on points with second-placed Marseille, who have one match in hand.

Donnarumma's face was bloodied after the Italy international took Wilfried Singo's studs in the 17th minute. Singo, whose shot had been blocked, tried to jump over the sliding Donnarumma but instead struck his face, lucky to avoid a red card.

Donnarumma was left lying on the pitch while receiving treatment. He finally stood up and walked away to be replaced by Matvey Safonov.

Desire Doue had put PSG in front in the first half before Eliesse Ben Seghir levelled from the penalty spot after the interval and Breel Embolo gave Monaco the lead at the hour mark.

Dembele then scored his first goal of the evening from a rebound in the 64th minute. He added more luster to PSG's win deep in added time when he completed his brace.

The match was brought forward because of a scheduling conflict with the Trophee des Champions between the two clubs on January 5 in Doha during the weekend that the French league resumes.