Arsenal will need to score at Atletico Madrid next Thursday, and they may well need to score twice. Against the best defensive team of their generation, who have conceded just 18 league goals all season and just four in 17 home league games. So far in this year’s Europa League they have kept home clean sheets against Copenhagen, Lokomotiv Moscow and Sporting CP.

So to make it through to the final in Lyon, and give Arsene Wenger the perfect goodbye, Arsenal will have to do one of the hardest things in football: breach the Atletico defence in its own home. And of course they will have to do it without Pierre-Emerick Aubameyang, their best striker, who is cup tied in the Europa League.

That puts serious pressure on Alexandre Lacazette and Danny Welbeck and the big question from the first leg is whether they can find that ruthlessness in front of goal that they lacked at the Emirates Stadium.

Arsenal dominated possession, as they would at home against a non-possession team who played almost 80 minutes with 10 men. But for all the chances and half-chances they created, they could only manage one goal.

And on a night of predictabilities – Arsenal on top, Atletico defending but eventually scoring on the break – perhaps the most surprising moment was the way that Arsenal scored. Half-way through the second half Jack Wilshere swung in a cross from the left to the far post where Lacazette got up above Lucas Hernandez to head the ball past Jan Oblak.

The way that Atletico play is specifically geared to stop this from happening. Their narrow back four, conceding the flanks to the opposition, represents an acceptance that their opponent will swing in crosses, but also a confidence that Atletico will always be able to repel them. For so much of the night, they managed it: Diego Godin and his apprentice Jose Maria Gimenez have been doing this for years for Diego Simeone’s side, in even harder circumstances than for Arsenal away.

Diego Godin and Jose Gimenez are set-up to clear any crosses from the flanks (Getty)

So despite that second half header, there were still moments when Lacazette could have taken the tie away from Atletico, but did not. An early volley from a Welbeck cross, an effort Oblak saved from a Nacho Monreal pass. Oblak saved again from Welbeck with his legs in the first half and it is no wonder Arsenal see him as an attractive, if unlikely, potential upgrade on Petr Cech this summer.

Even after his goal, Lacazette whistled a near-post header wide from a corner while Oblak continued to stand strong, diving late to keep out Aaron Ramsey’s shot from distance. Beating this defence and this goalkeeper is so hard, but given the circumstances and the eventual away goal they conceded, Arsenal needed to do it more than once.

It almost made you wonder whether they could have done with another France international striker last night. In a game when the opposition lets you fire in cross after cross, and where you need someone who can challenge Godin and Gimenez in the air, what about a striker like Olivier Giroud?

Giroud may be the ideal striker to break down Atletico Madrid (Getty)