Arsenal might have taken the lead barely a minute into the match when Lucas Podolski struck from outside the box, but his effort moved wide of the post. Meanwhile, Olivier Giroud tested the palms of Jussi Jaaskelainen moments later.
The Gunners continued to dominate possession as the half advanced, with West Ham's main threat coming from the power of Andy Carroll. However, the Hammers took the lead with 21 minutes on the clock when Mohamed Diame bent an effort into the top corner from inside the box.
Arsenal continued to probe as the half advanced its latter stages and Giroud levelled the match with a tap in five minutes before the break to score his first Premier League goal for the club.
Both sides shared spells of posssession early in the second period, but Matt Jarvis fired the first real chance over the crossbar just before the hour mark. Meanwhile, Carroll remained the main outlet for the Hammers.
Arsenal's first real chance of the second period fell to Theo Walcott after 66 minutes, but he just fired wide from inside the penalty area. Meanwhile, Carroll headed an effort just wide for West Ham moments later.
The away side had a big penalty shout after 73 minutes when Aaron Ramsey was felled in the area, but no decision was forthcoming. However, they went into the lead three minutes later when Walcott finished from close range.
Kevin Nolan had a fine chance to level it moments later, but he fired over the crossbar from close range. They were made to rue the miss when Santi Cazorla fired in Arsenal's third ten minutes from time.