Lille effectively sealed victory in the Ligue 1 title race after a 53rd-minute goal from Gervinho yielded a laboured but vital 1-0 win at home to Sochaux.
Rudi Garcia's side, who beat Paris Saint-Germain 1-0 in Saturday's Coupe de France final to end a 56-year trophy drought, were dominant throughout, but their inability to put the game out of reach made for a nervy finale.
The win puts Lille six points clear of second-placed Marseille with two games left to play, and their goal difference is eight goals better than their nearest rivals.
"We're very, very close," said Lille captain Rio Mavuba. "Except for a catastrophe, we should have the title. We played with bravery tonight. It's not over yet but, to be honest, it looks good."
Lille will be assured of their first league title since 1954 if they pick up at least a point at Paris Saint-Germain on Saturday. "As long as it's not mathematically guaranteed, there you go," warned Lille coach Garcia. "But it looks good. I'm proud of the guys, playing a match like that four days after the final. Hats off to them."
Despite the stakes, there were no signs of nervousness among the Lille ranks as the hosts flew out of the blocks, with Gervinho in the thick of the action. The Ivorian had a penalty appeal turned down in the second minute after tumbling over Damien Perquis' outstretched leg before poking the ball against the near post from Eden Hazard's left-wing centre.
He looked poised to break the deadlock in the 18th minute only to produce one of the misses of the season, skipping around goalkeeper Teddy Richert, but then lifting the ball over the crossbar with the exposed goal gaping.
Lille sprang into attack once more in the second half and after Coupe de France final-match winner Ludovic Obraniak stung Richert's palms from distance, and Gervinho's luck deserted him again. From the resulting corner the ball arrived at the Ivorian's feet but his powerful close-range shot hit the post and ricocheted onto Sochaux defender David Sauget before somehow going over the bar.
Gervinho was not to be denied, however, and in the 53rd minute he made the vital breakthrough, collecting Moussa Sow's pass and bobbling a shot past Richert that hit the base of the left-hand upright and went in.
The home fans' hearts dropped with 20 minutes remaining after Modibo Maiga picked Aurelien Chedjou's pocket inside the Lille box, but Brown Ideye spooned his strike partner's cut-back over the bar.
PSG drop points at Bordeaux
In the day's other game, PSG squandered the chance to over-take Lyon in the battle for UEFA Champions League qualification after losing 1-0 at Bordeaux.
Bordeaux took a sixth-minute lead when Benoit Tremoulinas was pole-axed by Marcos Ceara inside the box and Cheick Diabate coolly wrong-footed Gregory Coupet with the resulting penalty.
The hosts were indebted to Cedric Carrasso thereafter, the Bordeaux goalkeeper saving well from Clement Chantome in the first half and producing two flying saves to repel Guillaume Hoarau and Nene in the second. The margin of victory would have been more handsome had substitute Anthony Modeste not hit the crossbar and then the post from close range in the dying stages.
Third-placed Lyon, who drew 1-1 at Brest on Monday, therefore remain two points clear of PSG in the race for third place and the final Champions League qualifying spot. Bordeaux, meanwhile, climbed into eighth place and also secured their top-flight status after consecutive losses to Sochaux and Lens had seen them slip towards the relegation zone.