Lille beat Sochaux 1-0 on Wednesday thanks to Gervinho's goal to go six points above second-placed Olympique Marseille with two games left and a better goal difference of eight.
Only the biggest of calamities can deprive the "Mastiffs" of their first league title since 1954 and a remarkable double for a modest club having won the French cup, also against PSG, last weekend.
"It's starting to feel good but it is not mathematically done. We will try everything to get the title in Paris," Lille coach Rudi Garcia told reporters.
"It's like the end of last season, we are coming off four straight victories. Apparently we've got a 93 percent of winning the title, I've heard that, it must continue."
They meet a PSG side whose hopes of securing the third Champions League qualifying spot were hit by a 1-0 defeat at Girondins Bordeaux on Wednesday, leaving the capital club two points behind third-placed Olympique Lyon.
At the other end the situation is just as tense with Monaco, European Cup finalists as recently as 2004, a point away from safety in the final relegation place with Racing lens and Arles-Avignon already having gone down.
One of France's most famous clubs looked to have hauled themselves away from trouble but last weekend's 1-1 draw with Lens, who equalised in injury time despite knowing they were relegated, seriously damaged the principality side's chances.
Montpellier still have the very slightest chance of making sixth and the final Europa League berth, meaning Monaco will have to show a fighting spirit so rarely seen this term.
