Barcelona boss Xavi says Eintracht Frankfurt fully deserved their stunning 3-2 victory in the second leg of their Europa League quarter-final tie at Camp Nou on Thursday.
Filip Kostic scored twice, the first of which came from the penalty spot, and Rafael Borre slammed in from long range as the Bundesliga side sealed a memorable 4-3 aggregate win over the Catalan giants, who scored twice in stoppage time through Sergio Busquets' fine strike and a Memphis Depay penalty.
The result ended Barca's 15-game unbeaten run, which was the longest in the top five European leagues, while it was only the second time in their last seven knockout ties in Europe when they have avoided defeat in the first leg that they have been eliminated.
Xavi had no complaints about the result and admitted his side were well off the pace they have set in recent months.
"We scored two goals but we weren't able to attack in the best way," he told a media conference.
"We didn't play as well as in other games and they came out very well on the counter-attack. They had that first penalty that went very well for them and then with a great goal with a silly loss from us on the right.
"We have had control but we haven't generated enough to hurt them, and they have done it with little [of the game]. With a penalty, with a counter from a loss from us and the third comes from a play after we had been pressing.
"They are mistakes that we have paid for. This is what happens in Europe and we leave disappointed.
"It's not a failure. We've tried. It's a disappointment because we had high hopes and we've put everything on the pitch, and in the end Frankfurt won. It's a competition and if there is failure we are going to learn.
"We can only congratulate them because they deserved it."
A significant number of Frankfurt supporters roared their side on, with far more than their allocation of 5,000 present in the stadium.
Xavi says that had an impact on his side and confirmed the club is looking into why there were so many opposition fans.
"The atmosphere hasn't helped us," he added. "We expected some 70,000 or 80,000 people from Catalonia and that hasn't happened. It looked like a final with divided support. I think the club is checking what happened."
Barca are next in action on Monday when they host Cadiz in LaLiga.