Barcelona was undone by Real Sociedad's potent attack 3-1 to relinquish the provisional Spanish league lead to Real Madrid after it eased to a 3-0 win over Elche on Saturday. Barcelona coach Gerard Martino tried to reinforce his defense by playing with two holding midfielders in Sergio Busquets and Alex Song. But Song scored an own goal in the 32nd minute in the first of several defensive lapses that doomed the defending champions and cancelled out Lionel Messi's 36th-minute equalizer. Antoine Griezmann restored the hosts' advantage after an error by defender Marc Bartra in the 54th before setting up David Zurutuza in the 59th with Barcelona turned into bystanders. Barcelona and Atletico Madrid trail Madrid by three points. Atletico plays on Sunday. (For more sports news and updates, follow Ahram Online Sports on Twitter at@AO_Sportsand on Facebook atAhramOnlineSports.) http://english.ahram.org.eg/News/94977.aspx