Goals from Gabriel Marinellii and Emile Smith Rowe were enough to give Arsenal the desired three points to shoot them above West Ham who has retained the fourth position for weeks.
Marinelli struck three minutes into second half to give dominant Arsenal their second consecutive victory in the English Premier League after losing to Everton on December 6.
Substitute Emile Smith Rowe doubled the lead at the 87th minute ensuring that nothing is left for West Ham in the game.
The Gunners who are now one point above of West Ham with 29, are seven points behind third placed Chelsea who plays tomorrow against Everton who have gained 18 points from 16 games so far.
West Ham struggled to find their rhythm in the game and got their issues compounded when Vladimír Coufal was sent off at the 68th minute for picking a second Yellow Card.
West Ham were initially used prolific have won just one out of their last six games, a record that have seen them drop down into Europa League Zone.
Arsenal seeking to retain their top four positive in the busy festive period fixtures will travel to Leads on December 18, while West Ham will host bottom placed Norwich on the same day.
