"You do it too, eh?".

Those were the words from Arsenal's set-piece coach Nicolas Jover to Bayer Leverkusen manager Kasper Hjulmand after the German side took the lead from a corner in the Champions League last-16 first-leg tie between the two sides.

They struck having almost scored seconds earlier from an excellently-worked routine from the kick-off to start the second half, with David Raya tipping Martin Terrier's header over.

From Alex Grimaldo's set-piece, captain Robert Andrich was left free to nod in at the back post.

It was the first time the Gunners had been behind in this season's Champions League.

German forward Kai Havertz, who spent 10 years at Leverkusen before being sold to Chelsea for £71m in 2020, came off the bench to slot in the 89th-minute equaliser after Noni Madueke was brought down in the box.

Jover's comment to Hjulmand was also sparked by some from the Leverkusen head coach about how Arsenal use their physicality at corners to gain an advantage.

"I think there was a little bit of misunderstanding of my press conference yesterday and I was challenging the way things Arsenal are doing offensive blocks," said Hjulmand.

"We do it also. We do offensive blocks and we do it to make space. I was just questioning whether it is in the rules to body check and take a player out to make space.

"He [Jover] just said, 'You do it too, eh?'. It's the same for all teams, we are all doing it."

Gunners boss Mikel Arteta was disappointed to concede from a set-piece, not only because of Arsenal's own prowess from corners but because he showed his team "three clips" of Leverkusen's well-worked routines from kick-offs.

Before the tie at the BayArena, Arsenal had conceded only 11 goals from set-pieces in all competitions, level with Manchester City. Only Wolves (10) and Everton (9) had conceded fewer.

"There's always two sides to that," added Arteta. "One is the element of the opponent that they picked that weakness, and that lack of attention or urgency in both situations.

"And the other one is us, because we knew. We showed them three clips from last weekend in three different ways, and we weren't ready for it, and we got caught."

Havertz' late penalty against his former club put a different perspective on what was a disappointing performance from the one Arsenal would have hoped for.

Arteta felt the game had "different phases" and his side were "very dominant" in the first half, but did not take the early chance they had when Gabriel Martinelli's powerful shot hit the crossbar.

He also unusually took off key player and captain Bukayo Saka after a below-par display, but his replacement Noni Madueke won the penalty that saw Arsenal avoid defeat in the competition for the first time this season.

Leverkusen were not happy with the penalty award as Malik Tillman's torso seemed to make contact with Madueke's foot as he dribbled into the box.

But Havertz kept his cool to ensure Arsenal remain favourites in next Tuesday's return at Emirates Stadium.

"We are confident we will get the job done in London. The manager said just go on and try and change the game," said Madueke.

"I don't really know what happened [for the penalty] I just know I felt contact, went down and penalty.

"Kai Havertz has been scoring high-pressure penalties all his career, top composure to step up. Really pleased, not just for him but the team as well.

"When you come on and your team is losing it gives you that extra impetuous to try and change it."

Arteta was "not surprised" with Madueke's impact as it was his "biggest quality."

"He's very brave at doing that and Noni is a real threat. To have a player with that ability when you need him and to step in in the manner that he did, big credit to him," added the Spaniard.

Arsenal have avoided defeat in the first leg in four of their last five knockout games in the Champions League (W2 D2 L1), going on to progress in two of the previous three ties.

But in their previous 16 matches at this stage of the competition, they have lost nine and progressed seven times.

Arsenal are still competing for trophies in four competitions and aiming to claim their first silverware since an FA Cup triumph in 2020.

Arteta was pleased his side remained composed when going behind to leave Leverkusen with a draw.

"Yes, that's why I said emotionally it becomes a very different game because that is a team that is very, very good in transition, and you have more hurry and more rush to create danger and to go and draw the game, and you can get caught while doing that," he said.

"I liked that emotionally, we understood what we had to do.

"The level of execution obviously has to be better and it will be better in the second leg. We'll adapt a few things and yes, we'll move on."