Barcelona have won the first El Clasico of the season with a 3-1 victory over Real Madrid at the Santiago Bernabeu.

The hosts took a dramatic lead after 22 seconds when Mesut Ozil intercepted goalkeeper Victor Valdes' clearance before his shot spun into the path of Karim Benzema, who poked in.

Barca's first effort on goal came after six minutes when a typically weaving run from Lionel Messi ended with the Argentine's shot being palmed away by Iker Casillas for a corner.

At the other end, Cristiano Ronaldo tested Valdes with a fizzing shot, which the goalkeeper punched clear.

The Portuguese forward should have doubled his side's lead on 24 minutes, but he screwed his shot wide from the edge of the penalty area with a clear sight on goal.

The visitors went in level at the break after Alexis Sanchez had fired into the bottom corner from 12 yards following Messi's threaded through ball on 30 minutes.

Pep Guardiola's side turned the match around in the 53rd minute when Xavi Hernandez's shot crept into the net thanks to a big deflection off the heels of Marcelo.

Los Blancos should have equalised just after the hour, but Ronaldo somehow directed his header wide from six yards out after Xabi Alonso's cross.

The away side punished the miss a minute later as Cesc Fabregas nodded in Dani Alves' cross at the back post following a quick counter-attack.

Chances for Benzema and substitute Kaka could have set up a nervy final 10 minutes, while Andres Iniesta almost gave his side a fourth goal at the other end.

The win has sent the Catalan club top of the La Liga table on the head-to-head ruling, albeit having played one game more than Madrid.