Relive how the 90 minutes of action unfolded with Sports Mole's live text coverage below.
STARTING XI: Cech; Bellerin, Mustafi, Sokratis, Monreal; Guendouzi, Xhaka; Iwobi, Ramsey, Mkhitaryan; Aubameyang
SUBS: Leno, Holding, Lichtsteiner, Elneny, Torreira, Welbeck, Lacazette
STARTING XI: Fabianski; Fredericks, Balbuena, Diop, Masuaku; Sanchez, Wilshere; Anderson, Snodgrass, Antonio; Arnautovic
SUBS: Adrian, Rice, Zabaleta, Obiang, Yarmolenko, Lucas, Hernandez
Unai Emery: "After the first two matches, we have two defeats and we need to win this match against West Ham. I think it's very important to show a better performance than in the two first matches. We are preparing well, I am feeling well when I look at the players in training every day."
Manuel Pellegrini: "You can see what happened at Manchester United after Sir Alex Ferguson finished. There have been a lot of different players, no titles, a lot of criticism. They were so used to winning with that manager, but when you make a change it is not easy. I think that Arsenal are going through the same thing."
ARSENAL SUBS: Leno, Holding, Lichtsteiner, Elneny, Torreira, Welbeck, Lacazette
WEST HAM UNITED SUBS: Adrian, Rice, Zabaleta, Obiang, Yarmolenko, Lucas, Hernandez