Mikel Arteta says Arsenal will learn from their painful defeat to Porto in the first leg of their Champions League last-16 tie.
The Gunners were beaten 1-0 by the hosts, who broke the deadlock with a wonder strike by Galeno in the 94th minute.
Until then, it had been a cagey game and - despite dominating possession - Arsenal failed to have a single shot on target.
This was the Gunners first Champions League knockout tie in seven years and, of their starting XI, only Kai Havertz had played in such a game before tonight.
“Obviously I am very disappointed the way we gave the game away at the end, not managing that situation well enough,” said Arteta.
“You get punished in the Champions League. If you cannot win it, you don’t lose it.
“We really dominated the game but we lacked purpose, especially in the first-half. You need to have much more aggression, you need to break lines, to play forward and generate much more threat on that backline.
“In the second-half there were much better things and we generated a lot of situations, without really creating much from it.
“We will learn from it. Now it is clear, it is half-time. If you want to be in the quarter-finals you have to beat your opponent and that will be the purpose and the plan, with all our supporters together.”
Arsenal had been in brilliant form before this defeat, winning five games on the spin and scoring 21 goals in the process.
They did not once trouble goalkeeper Diego Costa, though, and were guilty of giving the ball away late on for Galeno to score.
Arteta admitted his side cannot afford to do that, but he defended them against claims they were naive.
“Well it’s only the last ball, so if in 94 minutes they haven’t had any naivety other than that one, I think it’s a bit cruel to judge it,” he said.
“But it’s true that it has had a big impact on the result. A lot of other things they did for the first time here were very good.”
