Barcelona manager Xavi said his team "can't be happy" after needing extra time to defeat third-division Intercity 4-3 in the Copa del Rey Round of 32 on Wednesday.
Barca looked on course for a routine win at Estadio Jose Rico Perez when Ronald Araujo put the visitors in front in the fourth minute, but Oriol Soldevila Puig pulled Intercity level just before the hour mark. Ousmane Dembele restored Barcelona's lead seven minutes later, only for Puig to strike again to restore parity.
Moments later, Raphinha made it 3-2 but there was still time for another twist as former Barca Academy player Puig completed his hat-trick with four minutes remaining. It was left to substitute Ansu Fati to eventually win the game for Barcelona, with the Spain forward striking in extra time.
"We can't be happy but these things can happen in the Copa," Xavi said. "We gave them too many chances in a game that we had under total control. We played well but not in either penalty box.
"We didn’t stop crosses, we didn’t defend our penalty area well. We can’t come away from the game feeling happy. Our general play was quite good but we need to be more convincing."
Shock avoided but it continued a less-than-impressive restart to the season for Barcelona, who were held to a 1-1 La Liga draw by local rivals Espanyol in their first match after the World Cup. Combined with Real Madrid's win at Real Valladolid, the two Spanish giants are level on points at the top of the table.
However, Xavi insisted that his players are not struggling for form following their exploits in Qatar and the six-week break since the club season was halted.
Next up for Barca is a La Liga trip to fourth-placed Atletico Madrid on Sunday, but the Catalans will have to contend with the absence of star striker Robert Lewandowski, who will serve the second of a three-match suspension.
"We’re playing well. We played brilliantly in the first half against Espanyol. And I’m happy with how we played today," Xavi said. "We’re not clinical enough but we’re playing well. We need to be more convincing in both penalty areas. I have to think that we can do better.
"We’ve got time to get ready for Sunday’s game [against Atlético Madrid]. We have to accept that Robert Lewandowski won’t be available.