A Gregorz Krychowiak penalty sealed the points for the home side.
Lyon’s title ambitions suffered a huge setback as they were beaten at Stade Reims.
The away side had Milan Besavic sent off for a foul on Diego Rigohato in the box and Krychowiak scored the resulting spot kick.
The win reassures Reims that they can steer clear of relegation after returning to the top flight for the first time in 33 years last season.
For Lyon however their chances of stealing the title from PSG now seems unlikely as they are left 11 points off the pace in fourth.