Barcelona moved 10 points clear of Real Madrid in La Liga with an uncharacteristically staid 1-0 win over Real Zaragoza on Saturday.Seydou Keita was the unlikely hero at the Camp Nou, notching just his second goal of the season two minutes from half-time to secure Barca's fourth straight league victory.Barca was lacklustre in the first half before Lionel Messi sparked the Spanish champions into action, sweeping a cross to Keita at the far post for the Malian defender to tuck past Zaragoza goalkeeper Dolbas.It was just reward for Keita, who had earlier had a goal controversially disallowed for offside.Pep Guardiola was a less animated figure than usual on the touchline, the Barca boss still suffering from a back injury that necessitated his hospitalisation on Thursday.Real Madrid will have a chance to reduce the gap to seven points when they take on Racing Santander on Sunday.Elsewhere, Villarreal's top-three hopes suffered a blow with a 3-1 loss at Atletico Madrid.Jose Antonio Reyes put Atletico in front five minutes in with a fine curling effort from 20 yards out, but Giuseppe Rossi drew Villarreal level with a left-footed redirection of Santi Cazorla's free kick after 33 minutes.But Atletico responded after the break with quick goals to Sergio Aguero (69) and Diego Forlan (72), the former played in to the area by Filipe Luis for an easy finish and the latter converting from close range on Reyes' good work.Finally, Pablo Hernandez scored in either half as Valencia ran out 2-1 winners at Mallorca, leaving the visitors well placed to clinch third spot behind Barca and Real.