Lyon's title aspirations took a big hit on Saturday as Florian Thauvin scored a goal in each half to lead Bastia to a 4-1 home win against Lyon.
The visitors entered the weekend four points back of leaders PSG, but the capital club now has the opportunity to take a seven-point lead with a win at St Etienne on Sunday.
Thauvin brought the game to life one minute before halftime when he was played in behind the Lyon defense by Wahbi Khazri before slotting his shot past goalkeeper Remy Vercoutre.
Lyon leveled the match in the 54th minute through Lisandro Lopez, who got on the other end of a free kick from Yoann Gourcuff to notch his ninth goal of the season.
But Bastia quickly restored its lead within two minutes as Khazri played provider once again, cutting the ball back for Anthony Modeste to fire home.
Thauvin made it 3-1 to the home side just after the hour mark when he tracked down Modeste's through ball and beat Vercoutre, while Khazri capped the scoring three minutes from time with a nice curling effort.
Bastia moves five points clear of the relegation places with the win.
In Saturday's other action, Salomon Kalou scored a goal in the seventh minute for Lille, but put his team behind to Evian in the 67th with an own goal. His day then got worse as he failed to convert from the penalty spot six minutes later, leaving his team with a 2-1 defeat.
Lorient rolled to a 4-0 victory against Brest as four different players found the net, Corentin Jean tallied the equalizer in the 50th minute for Troyes, which claimed a 1-1 draw at Montpellier, Sochaux had to settle for a 1-1 draw at home against Valenciennes when Opa Nguette netted the equalizer in the 82nd minute and Reims downed Rennes, 1-0, with Mohamed Fofana tallying the only goal in the first half.