Lille's title aspirations suffered an unlikely setback as they were beaten 1-0 at relegation-threatened Monaco.
Monaco began the day in the drop zone but Park Chu-young's goal after ten minutes was enough to beat the leaders, whose challenge was further unhinged by the 37th-minute dismissal of Gervinho.
Lille's defeat means their closest challengers Marseille can bridge the four-point gap at the top when they host mid-table Toulouse on Sunday.
Their other title rivals, third-placed Rennes, suffered a shock 2-0 defeat away to Brest.
Nolan Roux put the hosts ahead against their fellow Breton outfit and as Rennes pressed for a leveller, they were sucker-punched by Bruno Grougi's 55th-minute strike to seal an unlikely win.
Paris St Germain boosted their bid for a Champions League berth with a workmanlike 2-1 victory on the road at Caen.
PSG had gone four games without a win prior to the game but goals from Christophe Jallet and Clement Chantome in either half lifted the fifth-placed capital club to three points which keep them in touch with the top three.
Bordeaux's woeful season took another hapless turn as they failed to score in their 0-0 draw with rock-bottom cannon fodder Arles.
Bordeaux came into the match in eighth and struggling to even qualify for the Europa League and, despite having some chances on Saturday, the hosts hardly dominated their lowly visitors at the Stade Chaban Delmas.
Auxerre slipped into the Ligue 1 relegation zone despite twice coming from behind to earn a 2-2 draw at home to St Etienne.
Emmanuel Riviere gave Les Verts the lead but Dennis Oliech levelled before half-time. Pierre-Emerick Aubameyang restored St Etienne's advantage but Dariusz Dudka's 79th-minute goal ensured the points were shared at the Stade de l'Abbe-Deschamps.
A 93rd-minute goal from Marama Vahirua earned Nancy a 1-1 draw with Valenciennes that does little to help either side.
In a fiery affair, which saw two men sent off, Gregory Pujol put the home side ahead three minutes before half-time, and that looked like being enough until Vahirua`s late contribution.
Lorient and Sochaux played out a 1-1 draw that does little to alter the fortunes of the mid-table outfits.
Boukary Drame's first ever Ligue 1 goal opened the scoring for the visitors after 25 minutes but Jeremy Morel ensured it ended honours even when he slotted home the equaliser ten minutes later.