Barcelona coach Luis Enrique refused to point the finger at his defence after the Catalans went down 3-2 to Paris Saint-Germain in Champions League Group F.
"I don't like to evaluate individual performances when we lose a game. We are all responsible, above all me," he said after suffering his first defeat since being appointed in the summer.
"We will analyse in depth what we did wrong to try and ensure these things don't happen again."
Barca had received praise after going unbeaten through their opening seven matches this season, keeping seven clean sheets in the process.
However, with Marc-Andre ter Stegen selected in goal rather than Claudio Bravo and with Gerard Pique left on the bench, Barca's defence was made to look ordinary.
David Luiz put the French champions ahead in the 10th minute, breaching the visitors' defence for the first time this season after 640 minutes, and PSG's smallest player Marco Verratti was allowed to head in a corner to make it 2-1 after Lionel Messi had equalised with his 68th Champions League goal.
Blaise Matuidi added a third, and while Neymar pulled another one back, Barcelona could not equalise and slumped to a fifth loss in nine Champions League away games.
"We committed very clear errors in bringing the ball out from the back," added Enrique. "From set-pieces they are very strong, and when you are behind it requires an awful lot of effort to try and get back into the game."
However, he said his side were perhaps unfortunate not to come away with a draw after putting their hosts under constant pressure in the closing stages.
"We already knew their potential. They are candidates to win the Champions League; they won their league last season.
"We were up against a rival of the same level as us and the difficulties we had were normal in such a game, but in the last 25 minutes we could have equalised.
"In the end I think we could have drawn and it would have been a fair result."
Barcelona were unable to build on their opening Group F win against APOEL two weeks ago, although a 1-1 draw between the Cypriots and Ajax in the night's other game did little to help these sides' prospects of progressing to the last 16.
- Win relieves pressure on Blanc -
Meanwhile, it was a night of great satisfaction for Paris coach Laurent Blanc, who had been under growing pressure following his team's sluggish start to the season, even if they have yet to lose a match.
The Ligue 1 club drew 1-1 at Ajax a fortnight ago and came into this encounter without injured talisman Zlatan Ibrahimovic as well as Ezequiel Lavezzi and Thiago Silva.
Despite that, they went one better than in April 2013, when a 2-2 draw against the same opponents led to them being eliminated from the competition in the quarter-finals.
"I am very satisfied. I think for those who like Paris Saint-Germain and French football it was a good evening," said Blanc, whose side are five points behind leaders Marseille in Ligue 1 yet harbour ambitions of going all the way in the Champions League.
"I will remember this win, as will the players and all those who were at the stadium. We do this job to live nights like these."
"I don't deny that our start to the season has been a bit more complicated than we wished, but tonight, the smell, the Champions League, Barcelona, subconsciously you are more determined.
"On nights like tonight you either rediscover your team or find yourself at the bottom of a hole."
Blanc, who was a team-mate of Luis Enrique at the Camp Nou for a season in the 1990s, added: "They hadn't conceded a goal yet. With the staff we have watched a lot of their matches and we realised that in all of them their opponents had chances to score goals.
"I played at Barcelona and I know that as a defender they take lots of risks. We had an inferior amount of the ball, which is rare, but despite that we created chances and scored three.
Source: AFP