Lille thrashed Nice 3-0 on Sunday afternoon to move two points clear at the top of Ligue 1.
The match was a classic case of the old adage "two points from nowhere" as Lille came from behind to secure all three points against their bitter rivals.
Nice started brightly and had the better of the opening exchanges but it was Lille who took the lead after just six minutes when Jean Michael Seri scored with a powerful strike from outside the box.
Nice fought back valiantly but it was Lille who doubled their advantage eight minutes later when Youssouf Fofana found space on the left wing and curled a perfectly placed shot into the top corner.
The French champions were then awarded a penalty after a handball by Nice defender Benjamin Mendy and Edinson Cavani slotted home the spot-kick to make it 3-0 and put the game beyond Nice's reach.
The result means that Lille now sit five points clear at the top of the table and have a comfortable cushion over second-placed Paris Saint-Germain.
Lille coach Christophe Galtier praised his side for their determination and fighting spirit, saying: "We knew it would be difficult, we expected it."
But he also acknowledged that Nice were a tough nut to crack and said: "It wasn't easy. We had a lot of pressure but we managed to keep our cool and get the result."
Nice manager Lucien Favre admitted defeat was a harsh lesson for his team, saying: "I'm very disappointed because I think we deserved more than this."
He added: "We had chances but we didn't take them and they punished us. It's not a good feeling."
With just nine games remaining in the season, Lille will be looking to continue their winning ways and maintain their lead at the top of the table. The club will be hoping to build momentum towards the end of the campaign and secure a place in the Europa League next term.