Ernesto Valverde has confessed that "the result is not good" for Barcelona after going down 1-0 to rivals Espanyol in the first leg of their Copa del Rey quarter-final tie.

Substitute Oscar Melendo scored late on at the RCDE Stadium on Wednesday night to give the Periquitos a slender advantage ahead of next week's return fixture.

Lionel Messi had earlier missed a penalty for Barca, who have won the competition three years running, and manager Valverde admits that his side were too profligate in front of goal during the defeat - their first in any competition since August.

"Despite suffering in strategic situations, sometimes it seems that you suffer more because of the environment than the chances," he told reporters after the match. "But their approach was to sit back and wait for us, closing any interior spaces. It was hard for us, but we had it under control.

"We were not successful in goal situations. The penalty save reactivated the crowd - there was some tension and then they scored. We wanted to do the same as always [in terms of the way they approached the game], but they defended well, they got it right in the move for the goal and Diego Lopez's penalty stop. We have to come back.

"The favourite at the end is the one who is winning, who has an advantage, in the same way as when we drew against Celta Vigo [in the last 16]. The result is not good for us. We have to play at home, but they'll try to score. It's the cup and you have to play until the end."

Barca, who had gone 29 matches without losing a game, return to action on Sunday night with a trip to Real Betis in La Liga.