Lens notched their seventh successive win to beat Toulouse 3-0 on Friday and move four points clear of Paris Saint-Germain at the top of Ligue 1.
Lens have held top spot since November 30 and will stay there for at least another fortnight as next weekend is given over to the French Cup.
After an even first 20 minutes, the game turned when Toulouse striker Emersonn was sent off for an ugly challenge on Odsonne Edouard.
Lens did not benefit from the one-man advantage until the start of the second half when they laid siege to the Toulouse goal.
Wesley Said broke the deadlock with a curling shot in the 57th minute before captain Adrien Thomasson added a second in the five minutes from time.
Pierre Ganiou sealed the points with a fine strike in the 90th minute.
On Saturday, fourth-placed Lille will press their claims when they host Rennes while Liam Rosenior, who is tipped as a possible candidate for the vacant manager's role at Chelsea, will take his Strasbourg side to Nice.
Marseille face Nantes on Sunday with the Paris derby closing out the weekend.