Abdoulrazak Boukari scored against his former club as Rennes saw off Lens 2-0 to take top spot in Ligue 1.
Boukari only made the move to Stade de la Route de Lorient in January, but fired Rennes in front after 14 minutes before Victor Hugo Montano wrapped up the points in the 71st minute.
The win moves Rennes one point ahead of the chasing pack, but it may only be a short stay as nearest challengers Lille play Lyon tomorrow.
Nice finally brought an end to their dismal away form with an impressive 2-0 victory at St Etienne.
Eric Roy's men had not won on the road since the second round of Ligue 1 matches, but managed to conquer their homesickness thanks to strikes from Kafoumba Coulibaly and Anthony Mounier.
Bordeaux eased the pressure on coach Jean Tigana with a 3-0 win over Auxerre. Alou Diarra, Anthony Modeste - from the penalty spot - and Jaroslav Plasil were all on target for the home side as they made amends for last week's 5-1 hammering at the hands of Lorient.
Caen came from two goals down to earn a 2-2 draw that leaves Monaco still inside the bottom three. Two goals from Park Chu-young, including a penalty, looked to have earned the home side the points, but Youssef El Arabi gave Caen a chance with 23 minutes remaining before Yohan Mollo levelled with a free-kick.
Larsen Toure's second-half equaliser ensured Brest were not upstaged by strugglers Arles in a 1-1 draw. The basement boys had defied their lowly status to open the scoring through Kamel Ghilas seven minutes before the break.
Lorient had Francis Coquelin sent off but still battled out a goalless draw at Valenciennes.
The match between Sochaux and Montpellier also finished goalless with both sides reduced to 10 men by the end. Brown Ideye was sent off for the hosts with Emir Spahic seeing red for Montpellier.