Ligue 1 leaders Montpellier lost 2-1 at Lorient on Sunday to present second-placed Paris Saint-Germain with an opportunity to move level on points in the French title race.
Having beaten Marseille 3-1 in mid-week, Montpellier were bidding to go six points clear of their nearest rivals but instead they were undone by a Henri Bedimo own goal and an accomplished strike by on-loan Arsenal forward Joel Campbell.
It was only Montpellier's second league defeat since the turn of the year and it means that PSG will draw level with Rene Girard's team if they win at bottom side Auxerre later on Sunday.
Lorient had won just one of their previous 16 league games but the win put them two points clear of the relegation zone with six matches remaining.
Campbell committed a dreadful miss in the 67th minute, lifting the ball over the crossbar from eight yards after being picked out by Jeremie Aliadiere's low centre.
Montpellier would not escape a second time, however, as Bedimo inadvertently gave Lorient the lead two minutes later when he headed Mathias Autret's left-wing cross into his own goal.
It let Campbell off the hook and the Costa Rican international gave himself further reason to smile in the 77th minute when he cut in from the right flank before shaping a fine, left-footed strike inside the left-hand post.
Olivier Giroud brought Montpellier back into the game within seconds, deftly touching home a right-wing cross from Karim Ait-Fana to take his tally for the season to 20 goals, but the equaliser would not come.
Champions Lille kept a firm grip on third place and closed to within four points of PSG by beating Ajaccio 4-1.
Yoann Poulard put through his own goal in the 16th minute to gift the hosts the lead before Joe Cole scored with a low left-footed shot from 20 yards to register his first league goal since December 21.
Substitute Gianni Bruno claimed his first Ligue 1 goal by heading home an 81st-minute Eden Hazard free-kick before Hazard completed victory with a late penalty. Frederic Sammaritano scored an injury-time consolation for Ajaccio.
Fourth-placed Lyon, beaten 1-0 by Marseille in Saturday's French League Cup final, are now six points behind Lille and visit sixth-placed Toulouse on Wednesday, when 10th-placed Marseille host Caen.
Elsewhere, a crisp second-half strike by Bakary Sako brought Saint-Etienne a 2-1 win at home to Brest that lifted Les Verts to fifth and ended a run of four games without a win.
Bordeaux remain eighth after Benoit Tremoulinas' last-minute penalty rescued a 2-2 draw at Nancy and Evian are now a point behind in ninth after they romped to a 3-0 win at Valenciennes to record their fourth successive away win.
In the day's other afternoon kick-off, Sochaux gave their bid to avoid relegation a shot in the arm with a 1-0 win at home to Dijon that moved them level on points with fourth-bottom Caen.