Arsene Wenger accused Arsenal of naivety after they were pushed to the brink of another frustrating Champions League exit by Lionel Messi's brace in Barcelona's 2-0 win at the Emirates Stadium.
Wenger was infuriated his players failed to heed his warning to keep it tight at all costs in the last 16, first leg on Tuesday as Messi punished the hosts' careless defending with a clinical 71st-minute opener.
Messi then took advantage of a needless foul on him by Mathieu Flamini, stroking home the resulting penalty to leave Barca on the verge of reaching the quarter-finals for a ninth consecutive year.
It was a familiar tale of woe for the Gunners manager, who only this week had spoken publicly of his desire not to repeat the first-leg gung-ho tactics that had played a major role in Arsenal's five successive last-16 failures.
"Of course I'm disappointed. We lost it in a way we knew we could not give them," Wenger said.
"We were extremely guilty. It's very difficult to take. If we had to keep a 0-0 I would have been happy with that.
"They are better than us, everybody knows that, but we could have won the game if we had kept our discipline.
"We were impatient in the build up and lost balls we usually don't do.
"Once again, like against Monaco last season, we lost the game in exactly the same way. (It was) naive and that is frustrating. We just gave it away."
Wenger's anger was compounded because, for much of the match, he could have no complaints as Arsenal frustrated the European champions with a composed performance that could have yielded a lead if not for poor finishing.
"Barcelona master all aspects of the game and they have the players to punish you. But I felt there was room to beat them tonight. That is the frustration," Wenger said.
"We had an unbelievable chance in the first half and the way we finished was a problem.
"Then we lost a bit of cautiousness to defend. When you leave a counter-attack that is when Barcelona is most dangerous."
ALL BUT OUT
Now Wenger is left to survey the wreckage of Arsenal's latest European flop and he conceded there was virtually no chance of a miraculous escape in the second leg in Spain on March 16.
"Barcelona is 95 percent through certainly, but we want to go there and fight," added Wenger, who was less than impressed with the way the visitors often made a meal of their response to tough tackles.
"Not one goes down without shouting," he moaned. "I felt the referee was influenced but let's be honest, we didn't lose the game because of the referee."
Barcelona defender Gerard Pique will miss the second leg after a late booking which followed a touchline chat with boss Luis Enrique, prompting suggestions it was a deliberate move to get a ban out of the way before the last eight with the tie effectively over.
But Luis Enrique denied that charge, saying: "No, it wasn't deliberate. if you see the foul, obviously he has to do it."
The coach was much more comfortable discussing his majestic side's 33rd consecutive unbeaten match.
"We managed to deal with Arsenal's pressure really well. We are one of the best clubs in the world when it comes to dealing with a tight defence," he said.
"We have had a really high defensive level. Arsenal had players to do us a lot of harm, but we were up to the challenge of all the dangers they could present us."
Few would bet against Barca winning their sixth European Cup this season, but Luis Enrique refused to write off Arsenal yet.
"The score is really good but nothing is decided yet. We will have to play really well in front of our own crowd to go through," he said.