Lille extended their Ligue 1 lead to four points over Marseille on Saturday, while Paris St Germain drew to move into third.
Pace-setters Lille went into the game against Nancy leading champions Marseille by a point and saw that advantage extended when Eden Hazard scored the only goal of the game on the stroke of half-time.
Paris St Germain moved into third despite being held to a draw by relegation-threatened Monaco at the Stade Louis II.
Adriano had given the principality club - who were just one point above the drop zone at kick-off - a 25th-minute lead, but Mevlut Erding equalised six minutes after the break to earn PSG a share of the spoils.
The result moves the capital club provisionally a point above Lyon and up to third ahead of OL's home game against second-placed Marseille.
Sochaux scored four times in the first half hour to improve their chances of playing in the Europa League next season and also harm those of Bordeaux, whose boss Jean Tigana resigned after the heavy defeat.
Brown Ideye scored twice, with strikes from Damien Perquis and Ryad Boudebouz sandwiched in between as they leapfrogged Lorient into sixth, while Bordeaux dropped to ninth with the loss.
Lorient dropped to seventh after being held to a goalless home draw by Toulouse.
Daniel Braaten first went wide early on for the visitors before Lorient then had the lion's share of the chances but could not find the net.
A first-half penalty from Alejandro Alonso helped St Etienne move into eighth place at the expense of rock bottom Arles.
Alonso netted from the spot in the 31st minute after Bobo Balde brought down Dimitri Payet in the box and the luckless Balde was then sent off four minutes later for a second bookable offence.
Relegation-threatened Auxerre withstood a battering to snatch a home win against Montpellier despite being outclassed at the Stade de l'Abbe-Deschamps.
The hosts went into the match 15th in Ligue 1 and just one point off the relegation zone but survived Montpellier's bombardment before Roy Contout came up with an undeserved winner 11 minutes from time.
Sixteen-year-old Mbaye Niang scored after a minute of his first Ligue 1 game as Caen reached the 40-point mark with a draw which did little to help Lens in their fight for survival.
Niang latched onto Kandia Traore's cross to give Caen the perfect start, but Raphael Varane got the equaliser in the 37th minute to ensure the points were shared.
The draw left Lens deep in trouble in 19th place with 31 points and needing big things out of their final four games.
Brest and Nice continue to have relegation worries after a goalless stalemate at the Stade Francis-Le Ble.