The bulky striker, who came on in the second half, powered home at the far post after connecting with Matthew Etherington's swerving cross.

The goal triggered a touchline brawl between Arsene Wenger and West Ham boss Alan Pardew who was celebrating close to the Frenchman.

The win moved the Hammers up to 15th place in the Premier League table on 12 points while Arsenal fifth on 17 points.

West Ham managed to contain their guests for the entire game but the Gunners were denied a clear penalty when Alexander Hleb was tripped by Jonathan Spector in the area.

Harewood wasted the match’s best chance in the 77th minute after springing free and going one on one with Arsenal keeper Jens Lehmann who stood his ground to clear the ball.