Elye Wahi put in an excellent performance as Lens came from behind to shock Arsenal in the Champions League, while Bukayo Saka suffered another injury.
Wahi’s first-time finish into the bottom left corner after a cross from Przemyslaw Frankowski saw the home side take the lead in the 69th minute.
The Gunners rode some early pressure from Lens before Gabriel Jesus opened the scoring after a 14th-minute through-ball from Bukayo Saka, who then went off injured.
Lens leveled with a superb finish from Adrien Thomasson, who curled into the far corner.
Saka went off after 33 minutes in another blow for Mikel Arteta’s side on a difficult night in Europe’s top-tier competition.
Lens XI: Nampalys Mendy, Brice Samba, Jonathan Gradit, Thomasson, Florian Sotoca, Przemyslaw Frankowski, Deiver Machado, Danso, Facundo Medina, Elye Wahi, Salis Abdul Samed
Subs: Jean-Louis Leca, Aguilar, Said, Fulgini, Maouassa, Yannick Pandor, Neil El Aynaoui, Morgan Guilavogui, Andy Diouf, Abdukodir Khusanov
Arsenal XI: Trossard, Zinchenko, David Raya, Martin Ødegaard, Jesus, Rice, Tomiyasu, Gabriel, Havertz, William Saliba, Saka
Subs: Cedric, M.Elneny, Jorginho, Partey, Nelson, Ramsdale, Ben White, Smith Rowe, Nketiah, Karl Hein, Jakub Kiwior, Fábio Vieira