Barcelona midfielder Javier Mascherano accepts they weren't at their best for victory over Real Madrid.

The Argentine says the battling performance will serve as a warning they cannot relax.

"They are difficult games, against opponents that push you to the limit, that are as good as our team. You need to try your hardest for every minute of the game, and that's what helped us to win. That's why we got the result we did," he said.

="Now we're four points ahead of Real Madrid. But this could always be turned on its head. The best thing is to always focus on the next game.

"We're aware that we didn't beat Real Madrid with our best football. Barcelona Football Club always likes to win, and especially to be better in a footballing sense, over and above the result."