Furiani, France (SportsNetwork.com) - PSG wasted an opportunity to move into a tie atop the Ligue 1 table by suffering a 4-2 loss at Bastia on Saturday.

First-place Marseille was handed a 2-1 loss by Montpellier on Friday to remain on 41 points, leaving the door open PSG to get on equal footing.

Things started brightly for the Parisians as goals from Lucas Moura and Adrien Rabiot handed the club a two-goal lead inside the opening 20 minutes, but it all went pear shaped after the half-hour mark.

Ryad Boudebouz converted a 32nd-minute penalty to cut the deficit in half while Francois Modesto equalized for Bastia just before halftime.

The second half belonged to the hosts as Julien Palmieri scored in the 56th and 89th minutes to seal all three points and doom PSG to second loss in three league outings.

Bastia is unbeaten in its last three Ligue 1 contests, putting the club on 21 points.

Guingamp scored in either half to collect a 2-0 victory over Lens on Saturday. Christophe Mandanne opened the scoring after only 18 minutes and Claudio Beauvue converted a penalty in the 76th minute to provide Guingamp with some insurance.

Nice, meanwhile, overturned a one-goal deficit to get three points from a 3-1 home win over Lorient.

Benjamin Jeannot put the visitors in front in the sixth minute, but it was a 29th-minute penalty from Eric Bautheac and second-half goals from Alexy Bosetti and Carlos Eduardo that proved to be the difference in the match.

Also on Saturday, Yoha Mollo and Romain Hamouma produced the goals to grant St. Etienne a 2-1 victory at Reims, Michael Frey netted the lone tally as Lille edged Caen and Adrien Thomasson and Paul-Georges Ntep De Madiba scored three minutes apart as Evian played to a 1-1 draw with Rennes.