Danny Welbeck returned to Manchester United as Arsenal's match-winner as the FA Cup holders secured a place in this year's semi-finals at Wembley. England striker Welbeck, who joined Arsenal from United in a £16m deal on deadline day in September, scored the goal that gave the Gunners their first win at Old Trafford since 2006. It ensures Louis van Gaal, the manager who sanctioned his sale, will almost certainly end his first season at Old Trafford empty-handed. Di Maria was first booked for diving, then tugged at referee Michael Oliver's shirt as he walked away, with inevitable consequences.