Frank Lampard's thrice-taken penalty took Chelsea four points clear at the top of the Barclays Premier League, while West Ham avoided dropping to the bottom.

Alessandro Diamanti put the home side in front from the spot just before half-time after Ashley Cole had brought down Jack Collison.

But Lampard equalised with an hour gone after Matthew Upson was judged to have fouled Daniel Sturridge, the England midfielder forced to take the spot-kick three times after referee Mike Dean saw players encroaching.