La Liga leaders Barcelona fell to a 1-0 defeat at Real Sociedad on Sunday as they had a Robert Lewandowski goal controversially disallowed. Sheraldo Becker's 33rd-minute goal consigned the Catalan giants to their second league defeat of the season, leaving Hansi Flick's side six points clear of second-placed Real Madrid, having played an extra match. Lewandowski's early disallowed strike led to furious debate over whether the Polish forward had been offside or not. Barcelona were without teenage star Lamine Yamal after he suffered a blow to his ankle in the Champions League win at Red Star Belgrade midweek and badly missed his spark.