Lens beat Ligue 1 leaders Paris St Germain 3-1 on Sunday to give the champions their first league loss of the season, narrowing the gap at the top between the two teams.
PSG were without Neymar, who was suspended after getting sent off against Strasbourg on Wednesday, and Lionel Messi who is continuing his post-World Cup recovery.
The result means Christophe Galtier's side are on 44 points from 17 games, four points ahead of Lens in second.
The hosts took an early lead after five minutes when a deflection from PSG keeper Gianluigi Donnarumma went to an unmarked Przemyslaw Frankowski, who volleyed the ball into the open net.
Hugo Ekitike equalised for PSG three minutes later when the striker reached a cross before Lens goalkeeper Brice Samba and tapped the ball in.
Lens striker Lois Openda restored his side's lead in the 28th minute when he got a through ball from Seko Fofana and ran into the box, where he beat defender Marquinhos before finishing into the lower-right corner of the goal.
French forward Alexis Claude-Maurice made it three for Lens two minutes into the second half to seal the win.
Shelton stops Tsitsipas, sets up Alcaraz showdown at US Open
Pegula powers past Cirstea as Romanian bids farewell to US Open
Alcaraz outguns Paul to reach US Open quarter-finals
Antonelli takes sensational home Italian GP win from back of grid
Arsenal pass Chelsea test in style with comeback win
