By Richard Martin BARCELONA (Reuters) - King's Cup holders Barcelona beat Real Sociedad 1-0 in their quarter-final first leg to end a 9-1/2 year barren spell at the Basque side while Atletico Madrid crushed Eibar on Thursday. Brazil forward Neymar won and scored a penalty in the 21st minute after being tripped by Aritz Elustondo to decide the game but spurned two clear chances after the break that would have given Barca a more comfortable lead in the tie. Sociedad had not lost to Barcelona at their Anoeta home in any competition since 2007 and could have struck an early blow when Willian Jose went down in the box in the first minute after a challenge from Gerard Pique but was denied a penalty. More...