Lionel Messi had a penalty saved early in the second half as Barcelona were held to a 1-1 draw at Valencia in a hard-fought Copa del Rey semi-final first leg on Wednesday night.
Valencia snatched a 27th-minute lead at their Mestalla Stadium when Jérémy Mathieu found space down the left wing and Jonas clipped the Frenchman's low cross high into the net past the goalkeeper José Manuel Pinto.
Pinto was lucky to be still on the pitch after television replays showed he handled the ball outside his area in the 18th minute but the referee waved play on.
Barça's captain, Carles Puyol, equalised 10 minutes before the break when he met a deep Cesc Fábregas corner and nodded past Diego Alves, who had come out to collect the ball but watched it sail over his head.
Alves, who has an impressive record saving spot-kicks, made amends 11 minutes into the second half when he flung himself to his left and parried away Messi's penalty, awarded after Miguel felled Thiago Alcântara in the area.
"He [Messi] is a player who doesn't give you much of a clue about which way he is going to shoot," Alves said afterwards. "You just have to hang in there and try to deceive him and today I was happy to be able to help the team."
The substitute Daniel Alves smashed a shot against the post after a brilliant one-two with Messi around 15 minutes from time but neither side was able to find a winner ahead of next week's second leg at Camp Nou.
It was Barça's third successive draw, coming after they were held to a 0-0 stalemate at Villarreal in La Liga on Saturday and last week's 2-2 Cup quarter-final draw at home to Real Madrid that sent Pep Guardiola's side through 4-3 on aggregate.
Guardiola, who was without the injured Andrés Iniesta, David Villa and Pedro and opted to rest Xavi, said that it was the best performance against Valencia he had seen from his players since he became coach in 2008.
"We created a lot of problems for them and they have always done the same to us, at home or away," the former Barça and Spain midfielder said. "It was a great result but the tie is not decided and now we need to win the return leg and see if we can make the final."
The eventual winners will play 23-times winners Athletic Bilbao or third-tier Mirandes in the final.
Mirandes, only the second team from Spain's Segunda B to reach the last four of the cup in its present format, gave themselves hope of pulling off another upset with a late goal in Tuesday's first leg at their tiny stadium in Miranda de Ebro as a Fernando Llorente double gave Bilbao a 2-1 success.