Lyon extended their lead at the top of Ligue 1 to 12 points as Lille slipped up away from home.
Gerard Houllier's side claimed their 12th win in 14 games, but the manner of their victory at bottom club Sedan was far from comprehensive.
The UEFA Champions League hopefuls required an 80th minute own goal from Nadjim Adbou to ensure they took all three points at Stade Louis-Dugauguez.
OL took the chance to extend their advantage at the top of the league knowing that closest challengers Lille had drawn 0-0 with Sochaux in the early kick-off.
Lens and Nancy both drew level with Lille on 25 points following home wins.
Georges Eo's Nantes were no challenge for Lens as they lost 2-0 at Stade Felix-Bollaert, with the goals coming from Adama Coulibaly (1) and Seydou Keita (82).
Nancy also triumphed when Sebastien Puygrenier's 76th minute strike gave them a 1-0 home win over Troyes.
Bordeaux are now three points shy of second place after taking another step to correct their mixed start to the season by beating Paris Saint Germain 2-0.
The clash in the capital saw Silva Wendel (28) and Lilian Laslandes score for the visitors.
St Etienne moved into fifth place, one point behind Lille, Lens and Nancy, courtesy of a 2-1 home win over Nice.
The hosts raced into a two goal lead through Frederic Piquionne (20) and Pascal Feindouno (26), but Nice were unable to build on Cyril Rool's strike on the brink of half-time as they fell to their eight defeat of the season.
Monaco's struggles continued as they could only draw 2-2 at home to Lorient.
Ivorian international Yaya Toure scored after eight minutes to give hope to the Principality outfit, but Hamed Namouchi (22) and Ulrich Le Pen (49) quickly cut ASM down to size.
However Jeremy Menez struck five minutes after the break to earn Monaco a point that means they move into 16th place in Ligue 1.
In the final game in France, Rennes drew 1-1 at home to Le Mans but were thankful for a late goal after John Utaka was dismissed on 40 minutes.
The striker's red card looked to have cost his side when Stephane Sessegnon scored late on in the first half, but Sylvain Marveaux struck with a minute to go in the game to rescue a point.
Click below for match summaries:
Sochaux 0-0 Lille
Lens 2-0 Nantes
Monaco 2-2 Lorient
Nancy 1-0 Troyes
Paris Saint Germain 0-2 Bordeaux
Rennes 1-1 Le Mans
Sedan 0-1 Lyon
St Etienne 2-1 Nice