Barcelona suffered its first league defeat of the season on Sunday, losing 2-1 to Atletico Madrid to blow the title race wide open. Atletico's Jose Antonio Reyes dribbled past two men before sending a long pass through for Diego Forlan, who shot first time past Victor Valdes in the 10th minute.
Simao Sabrosa scored Atletico's second when he curled a freekick into the right-hand corner of the net in the 23rd minute, while Zlatan Ibrahimovic volleyed in unmarked at the far post from a Barcelona corner just four minutes later.
Barcelona remains top, on 55 points from 22 matches, but Real Madrid, which beat Xerez 3-0 on Saturday, is only two points behind. Atletico is 11th on 27 points.
"Atletico played a good game, above all in defense," said Valdes. "In this stadium, it's always difficult for us." Earlier Sunday, Luis Fabiano scored the winner as Sevilla beat Osasuna 1-0.