French league front-runner Lyon needed a late own goal from defender Nadjim Abdou to beat last-placed Sedan 1-0 and open up a 12-point lead in the standings on Saturday.
Abdou turned the ball into his own net in the 80th minute after intercepting a cross from Lyon's Hatem Ben Arfa.
The win moved five-time defending champion Lyon onto 37 points from 14 rounds. Lille, which drew 0-0 at Sochaux, was second with 25 points.
Paris Saint-Germain lost 0-2 to Bordeaux suffering its second straight home defeat, putting more pressure on coach Guy Lacombe. Bordeaux's goals came from Brazilian Wendel and veteran striker Lilian Laslandes.
Saint-Etienne beat Nice 2-1 thanks to goals from Frederic Piquionne and Pascal Feindouno.