Lens condemned Arsenal to a first defeat of the season coming from behind at Stade Bollaert-Delelis to win 2-1 on matchday two of Champions League Group B.
The Gunners made the perfect start when Gabriel Jesus ruthlessly punished a defensive mistake on 14 minutes but that proved to be the high point on a night when Bukayo Saka limped off with an injury before half time.
Adrien Thomasson took advantage of a poor pass by David Raya to score the home side’s equaliser on 25 minutes and more sloppy defending after the break allowed Przemysław Frankowski space to cross for Elye Wahi to finish first time.
The Gunners did have chances to grab a late equaliser – substitutes Smith Rowe and Nelson both went close – but the home side stood firm to take the points.
“Congratulations to Lens. As we all saw, they are a really good side,” Mikel Arteta told TNT Sports. “It was an extremely exceptional atmosphere and a really difficult opponent.
“We made the most difficult thing in scoring the first goal and we had total control of the game. And in one action they managed to score and then it was game on again.
“We had a huge chance straight after the break with Leo [Trossard]. And two, three big chances. It’s true that we didn’t generate enough threat in the final third, like in many occasions we didn’t attack certain spaces and provoked certain jumps that for us are not good against them.
“But the difference from the PSV game [on matchday one]was the boxes. We had three or four big chances and we didn’t defend the box well enough to win the game.”
Reflecting on the build-up to Lens’ equaliser, which saw David Raya concede possession cheaply, the boss added: “Mistakes are part of football and they will continue to be there. But I think the difference was made in both boxes today, especially in the Champions League.
“You don’t generate 10 clear-cut chances in the Champions League. When you get there, you have to put the ball in the back of the net and you have to defend the box much better than we did.”
There was also an update on how Bukayo Saka got injured although the boss doesn’t know how serious it is and whether the winger will be available for Sunday’s crunch game against Manchester City.
“It was an action. It was a backheel and he felt something on that. The specific action it was nothing else. Obviously, he wasn’t comfortable to continue.”
With Saka unable to play more than 25 minutes and Gabriel Martinelli still sidelined by a hamstring injury, Arteta admitted his side were missing “a lot of threat” in the final third. All the same, he echoed the sentiment of Declan Rice by promising his players will learn from their first taste of Champions League football on the road.
“It was a big night for us. We didn’t manage to get the result that we want but we’ll take a lot of things from it and learn,” he concluded.
The Gunners go again in against Seville in three weeks’ time.