RC Lens' Elye Wahi scored one goal and set up another in a sterling performance to secure a 2-1 home win against Arsenal and put his side top of Champions League Group B on Tuesday.
The 20-year-old, who joined from Montpellier during the close season, fed Adrien Thomasson for the first-half equaliser after Gabriel Jesus's opener, before netting the winner in the 69th minute to send the Bollaert-Delelis stadium wild.
The result put the Ligue 1 side on four points from two games, one ahead of Arsenal who suffered their first defeat in the group stage of the competition in 10 games.
Sevilla are second on two points, one ahead of PSV Eindhoven after the two teams drew 1-1 in the Netherlands.
"Beating Arsenal in the Champions League will surely stay in our memories," Lens coach Franck Haise told a press conference.
"Elye is a young player, he only joined a month and a half ago, he's making big strides."
Arsenal coach Mikel Arteta, who had to cope with Bukayo Saka's early injury substitution, said: "The difference between today and PSV (when his side won 4-0) was in the boxes.
"There were moments in the second half we could have been more efficient. We took a big lesson today."
For Lens's first Champions League home game in 21 years, the ground was sold out for the 30th time in a row and the 38,000 crowd were not disappointed as their team continued a return to top form after a mediocre start to the season.
Lens had scored at least once in each of their last 33 home games in all European competitions, starting the run against Arsenal in the group stage of the Champions League in 1998-99, and they extended the streak on Tuesday.
EARLY CHANCES
The hosts had the first clear chances early on as Kevin Danso's attempt on the turn went just wide and Thomasson's header was slightly off target. Arsenal, however, were far more clinical, punishing Lens for their first mistake.
Thomasson lost the ball in midfield to Saka, who sent Jesus through and the Brazilian thumped his shot past Brice Samba to put the London side ahead after 14 minutes.
Samba's shot-stopping qualities were then put to the test by Kai Havertz but, just as Arsenal felt a sense of control, Thomasson made up for his earlier error in stunning fashion.
Wahi stretched to deflect Deiver Machado's long pass into the path of Thomasson, who curled the ball beautifully into the far corner to equalise after 25 minutes.
Saka, who limped off the pitch in Arsenal's 4-0 win at Bournemouth in the Premier League at the weekend, was replaced by Fabio Vieira 11 minutes from the interval.
"He tried a backheel and he felt something. It's muscular he couldn't carry on and we had to take him off," said Arteta.
The excellent Samba was then forced into an early save in the second half to deny Leandro Trossard.
Lens had a big opportunity in the 64th, only for Salis Abdul Samed's low shot to shave David Raya's left-hand post.
Samba again showed his worth three minutes later, making a spectacular save with his foot to frustrate Takehiro Tomiyasu.
Wahi was equally efficient at the other end, stroking Przemyslaw Frankowski's cross into the bottom corner to give Lens the advantage.
Arsenal had one last chance through Reiss Nelson but it was not to be their night.
