The Gunners came into the contest looking for a response after losing consecutive matches, including Saturday’s controversial 1-0 defeat to Newcastle.
And Mikel Arteta’s men nearly found one inside two minutes when a deep corner found an unmarked Kai Havertz at the back post, but the former Chelsea man made a complete mess of his headed effort.
The glaring miss did not deter the dominant hosts, who quickly began to move the ball with confidence and precision, forcing the visitors to drop deep into their own half.
While the Spanish side fought valiantly, their resistance was ultimately broken just before the half-hour mark. Jorginho’s inch-perfect pass between left-back and centre-half found the run of Bukayo Saka, who slid the ball across for Leandro Trossard to guide home his second goal of the UCL campaign.
After taking a narrow lead into the break, the Gunners made a brisk start to the second period, as they looked to put the game beyond doubt.
Havertz was inches away from doubling the advantage with a curling effort that drifted just wide of Marko Dmitrović’s far post, but it was only a matter of time until Arsenal grabbed a second goal through Saka.
After being sent into the box by Gabriel Martinelli, the England international chopped the ball onto his favoured left boot before firing into the bottom corner.
While their overwhelming dominance was deserving of a greater scoreline, the group leaders would have been pleased to claim the third win of their UCL campaign, moving them four points clear of Lens and PSV after four rounds.
As for the visitors, they are winless in 15 European away games and are rooted to the bottom with just two points to their name, and face a real battle to even drop into their coveted Europa League.
Flashscore Man of the Match: Bukayo Saka (Arsenal)
