Goals from Granit Xhaka and Danny Welbeck were enough to take all three points as scrap for the top four heats up.
Manchester United have not lost a match in the premier League since losing to Chelsea last October.
Arsenal came from the back of losing a north London derby last Sunday but changes to the line up saw a rejuvenated Arsenal and Arsene Wenger enjoyed his first ever Premier League win over Jose Mourinho .
Exciting day for arsenal fans.