Xavi was not entirely satisfied with Barcelona's performance despite a 1-0 win away at El Clasico rivals Real Madrid in their Copa del Rey semi-final first leg, and still believes their opponents are favourites for the tie.

An own goal by Eder Militao in the first half at the Santiago Bernabeu was enough for a Barca victory, while Madrid enjoyed plenty of the ball and had 13 shots, but did not hit the target once as they fell to defeat.

Barca's head coach was pleased with the win, but appeared eager to put the pressure back on Los Blancos ahead of the return leg on April 5 as he insisted they were still favourites to reach the final.

"We have a certain advantage," he told reporters. "We will have to compete very well [in the second leg at Camp Nou]. We have defended well. The return home, with our fans, is positive. But I still see Real Madrid as favourites."

Xavi was pleased with his team's defending, but concerned by their inability to keep the ball as the visitors claimed just 35.3 per cent possession in the game, completing just 309 of their 380 passes (81.3 per cent).

"I'm not satisfied... It's not the percentage we're looking for," he said.

"The result is very positive. I'm happy with the work, solid defence, we minimised Real Madrid on their field. The game was difficult.

"The victory is tremendous [but] we didn't know how to keep the ball, it was difficult for us to win duels. We defended well without the ball and fought well without the ball.

"The people are supportive. I am satisfied, but we have to improve in our game with the ball. We cannot give the opponent dominance.

"I am satisfied with the result but not so much for the match."