Manchester City manager Pep Guardiola refused to blame his defence for a Champions League last-16 exit in Monaco.
The Premier League side took a 5-3 advantage to the Stade Louis II but were breached twice inside the first half hour, with Kylian Mbappe and Fabinho on target for the Ligue 1 leaders.
A second-half improvement was rewarded with Leroy Sane's goal, which edged City ahead overall with 19 minutes remaining, but Tiemoue Bakayoko headed home to have the final word.
City's bold attacking play under former Barcelona and Bayern Munich boss Guardiola has often been compromised by a flimsy backline and an uncertain goalkeeping situation during his first season in charge at the Etihad Stadium.
Nevertheless, he was unwilling to give ground on a familiar line of questioning at a post-match news conference - insisting a lack of attacking intent and the collective failure of his team's pressing game when out of possession was behind an insipid first-half display.
"It's not about defence. Always we complain about goalkeepers and the defence, no. Today it was not," Guardiola said, after City became the first team in Champions League history to be eliminated after scoring five goals in the first leg of a knockout tie.
"In the second half was there a problem with the defence? No. The problem was in the first half we were not there.
"Our strength when the opponent has the ball is to go aggressive to pick it up and we didn't, in the right moment we didn't when we have done all the season.
"That is why we are out - we played 45 minutes. You have to play more than that but it is not about the defence and the goalkeeper.
"In the second half we won the second balls - how many chances did they create? Absolutely nothing [before Bakayoko's set-piece goal] - the same team.
"You cannot expect 90 minutes like the second half but the gap between the first and second was too big. In that situation, my feeling now is that we will learn from that and it will help us a lot in the future."
Six consecutive away clean sheets before being undone by Monaco supports the theory that his defence are not entirely without merit, but Guardiola must get to the root of why his team veered so far off message with a quarter-final place there for the taking.
"I tried to convince them from after finishing the Middlesbrough game [last Saturday's 2-0 FA Cup quarter-final win] and in all the meetings we had over these two or three days," he added.
"I said, 'Guys, go there and try to attack and try to go to score goals'. We did it in the second half, we did it in a lot of games, even when we lost.
"Today we were not able. Maybe we have to live more experience of that to know that it doesn't matter if we win or lose, but at least to be what we are.
"That is what I have said many times. We have to finish the game being what we are and what we have done from the beginning. We did it in the second half but in the first half we were not able to."