A minute to full-time, Senegalese right-back Youssouf Sabaly guaranteed victory for the hosts, with Sekou Mara providing the assist.
Defeat for Lens is a massive setback to their chances of booking a place in next season’s Europa League.
At the Stade Gaston Gerard, FC Nantes did their battle against relegation a lot of good by securing a 4-0 away triumph over already-relegated Dijon.
A brace from Randal Kolo Muani led Antoine Kombouare’s men past the Owls, while Mali forward Kalifa Coulibaly and Ludovic Blas completed the rout.
With this result, the Canaries are one point behind FC Lorient, Brest and Strasbourg heading into the last day of the season.