Manchester City completed the first ever domestic treble in English football. © AFP Manchester City completed the first ever domestic treble in English football in emphatic fashion by dispatching Watford 6-0 at Wembley to claim the FA Cup on Saturday. Raheem Sterling scored a hat-trick, while David Silva, Kevin de Bruyne and Gabriel Jesus also netted to cap a glorious campaign with the biggest margin of victory in a FA Cup final since 1903. Watford’s wait to win their first ever major piece of silverware goes on, but after going behind they had little answer to Pep Guardiola’s relentless champions as the Catalan picked up the 27h trophy of his coaching career. It could have been very different for the Hornets had Roberto Pereyra not missed the first big chance of the game after Watford pounced on one slack pass by Oleksandr Zinchenko to spring a counter-attack.Gerard Deulofeu fed the Argentine, but City goalkeeper Ederson raced from his goal to make a fine save with his trailing leg.Watford were also left angered as a handball shout for a penalty against Vincent Kompany was not looked upon favourably by referee Kevin Friend or the Video Assistant Referee.And Javi Gracia’s men also…