Second-placed Lens missed the chance to lead Ligue 1 after a 2-1 loss at Lorient. Aiyegun Tosin scored the decisive goal in the 65th minute, securing victory for the hosts.
Lorient took an early lead when Bamba Dieng converted a rebound in the 18th minute, marking his seventh league goal this season.
Lens responded in the second half as Odsonne Edouard finished from close range after a precise pass from Mamadou Sangare.
The hosts regained the advantage on their first shot of the second half, with Tosin firing past the keeper following a setup by Arsene Kouassi.
Lens remains on 56 points from 26 games, one behind Paris St Germain, who have a game in hand. Lorient climbs to eighth with 37 points.