Neymar was taken off on a stretcher deep into stoppage time as defending champion Paris Saint-Germain lost 1-0 at home to Lyon to drop to third place in the French league on Sunday.
Neymar incurred a left ankle injury in the seventh minute of injury time at Parc des Princes following a heavy tackle from Thiago Mendes, who was then red carded.
“No news about Ney(mar),” PSG coach Thomas Tuchel said after the game. “He’s with the physio and the doctors, and he will have some tests tomorrow.”
Lyon held on for 10 minutes of stoppage time to extend its unbeaten run to 11 games and throw the title race wide open.
PSG's fourth defeat of the season sent Lille top after it beat Bordeaux 2-1. Lyon is now second on goal difference, while PSG is one point behind in third spot.
“We were never ready to play this game. The team was very tired mentally, we made a lot of mistakes and didn’t play with enough rhythm and confidence," a dejected Tuchel said. “We did not concentrate enough. It’s a step backwards. I’m surprised, I was expecting a lot more.”
Fourth-place Marseille trails PSG by one point but has played two fewer games.
PSG was without captain and center half Marquinhos because of a hip problem and he was missed against Lyon's slick attacking trio of Memphis Depay, Karl Toko Ekambi and Tino Kadewere.
They have now combined for 18 goals and nine assists in 14 games, with Toko Ekambi setting up Kadewere to rifle a diagonal shot past goalkeeper Keylor Navas in the 34th minute after PSG's defense carelessly gave the ball away under no pressure near the penalty area.
“I think we could have won by more. We had a penalty for Depay which was totally ignored," Lille coach Rudi Garcia said. “The league is very tight and we did well to win tonight, so we can keep looking ahead.”
In northern France, Lille kept its strong form going and has lost only once in the league along with Lyon and Marseille.
Forward Jonathan Bamba scored the opening goal in the 16th minute and then set up captain Jose Fonte's header on the stroke of halftime, after midfielder Toma Basic had netted for Bordeaux.
PSG still has to play Lille twice and travel to Marseille and Lyon.
Rennes got back to winning ways with a scrappy 1-0 victory at Nice, thanks to striker M’Baye Niang's first-half goal.
In Sunday's other games, it was: Lorient 3, Nimes 0; Nantes 1, Dijon 1; Strasbourg 2, Metz 2; and Brest 2, Reims 1.
All the teams are back in action on Wednesday night.
PSG is at home to struggling Lorient, and Marseille has a tough trip to eighth-place Rennes. Lille visits last-place Dijon, while Lyon hosts Brest.