The Cameroon international headed home a Gael Clichy cross at the far post with two minutes remaining to finally beat Irons keeper Robert Green who had put in a previously faultless shift.
Arsenal dominated proceedings with plenty of possession and a high number of shots on goal and they finally wore down a courageous Hammers outfit who remain rock bottom of the league table. Arsenal's win kept them in second as they continue to chase the tail of league leaders Chelsea who are five points to the good.
Venue: Emirates Stadium, North London Crowd: 60,086 Referee: Miuchael Jones Yellow cards:ARS - Alex Song 25', Marouane Chamakh 82' WHU - Herita Ilunga 23', Luis Boa Morte 52'
ARS Lukasz Fabianski (gk), Bacary Sagna, Sebastien Squillaci, Gael Clichy, Laurent Koscielny, Cesc Fabregas, Samir Nasri, Alex Song, Denilson (Walcott 67'), Marouane Chamakh (Eboue 90'), Andrey Arshavin (Bendtner 79')
WHU Robert Green (gk), Herita Ilunga, Manuel da Costa, Danny Gabbidon, Lars Jacobsen, Valon Behrami (Barrera 90'), Luis Boa Morte, Scott Parker, Mark Noble, Frederic Piquionne (Cole 73'), Victor Obinna (Faubert 87')