Rio Mavuba scored a second-half winner as Lille moved a step closer to ending their half-a-century wait for a Ligue 1 title with a 2-1 victory at St Etienne.
Lille trailed to a fifth-minute goal from Emmanuel Riviere but Tulio De Melo equalised ten minutes later before Mavuba struck the decisive goal with 66 minutes played.
It meant Rudi Garcia's side opened up a seven-point gap over nearest rivals and champions Marseille.
Paris St Germain missed out on the chance to move into a Champions League qualifying spot after twice relinquishing the lead in their 2-2 draw with relegation-threatened Nancy at Parc des Princes.
Melvut Erding had fired the Parisians into an early lead but Landy N'Guemo equalised from the spot after Christophe Jallet saw red for his tackle on Julien Feret. Zoumana Camara restored the home side's advantage but Youssouf Hadji levelled and Nancy held on for a point despite Reynald Lemaitre's red card.
Antoine Kombouare's side remain fourth in the table, a point behind Lyon having played a game more while Nancy are a point from safety.