Arsenal suffered a turbulent night in the Champions League as Bukayo Saka hobbled off during defeat in Lens.
Bad weather grounded Mikel Arteta and his players at Luton Airport for five hours on Monday as their journey to France was delayed.
Now their hopes of avoiding a bumpy ride in qualifying for the knockout stages have also suffered a setback after Lens came from behind to record a 2-1 victory at a rocking Stade Bollaert-Delelis.
Gabriel Jesus thought he had given the Gunners lift-off when he broke the deadlock with his 22nd Champions League goal.
However, hopes of an easy night veered off course as an error from goalkeeper David Raya led to Adrien Thomasson levelling before Saka limped off hurt for the third time in nine days.
Elye Wahi then hit the winner with 20 minutes to go to open up Group B as Arsenal now face a tricky trip to Europa League holders Sevilla later in the month.
This was a first home Champions League game in 21 years for Lens and their fans were not going to miss the opportunity to enjoy the occasion.
A huge tifo, flares and a wall of sound greeted kick-off and their team certainly set about Arsenal in the opening exchanges, with Kevin Danso firing just wide after collecting a corner.
Despite the rapid start from the hosts, Arsenal struck first through Jesus’ tidy finish into the bottom corner after Saka had been gifted the ball by a sloppy backpass.
The noise inside the stadium remained despite Lens falling behind and the vociferous support were rewarded with an equaliser.
Raya, stood outside his box, looked to play a ball into midfield but the Arsenal goalkeeper’s pass was intercepted and moments later he was beaten by a fine curling strike from Thomasson to level the contest.
For the third game in a row, Saka then limped off injured having gone down off the ball.
He recovered after coming off late against Tottenham and Bournemouth but was replaced by Fabio Vieira here with the visit of Manchester City just five days away.
Leandro Trossard forced a smart save out of Brice Samba in the Lens goal at the start of the second-half as Arsenal looked to retake the lead.
The Ligue 1 side, though, started to take control of the game and Abdul Samed’s shot into the side-netting just after the interval was a warning for the visitors.
With the game opening up, Takehiro Tomiyasu had a great chance to turn home a corner but could only shoot straight at Mendy.
Lens would take the lead through Wahi, whose sweeping finish past Raya came after another break down the right flank.
Arteta responded with an immediate triple substitution as Ben White replaced Oleksandr Zinchenko with the ineffectual pair of Trossard and Kai Havertz taken off for Emile Smith Rowe and Reiss Nelson.
Despite the alterations, Samba was largely untroubled for the remainder of the night, punching clear a Smith Rowe drive with Arsenal unable to create a clearcut chance to rescue a point.