Juan Mata fired Chelsea into the lead in the 13th minute of play, following a pull-back from Fernando Torres.
However, Carlton Cole headed West Ham back in the game, before Mohamed Diame and Modibo Maiga hit late goals to give Sam Allardyce side a much needed victory in front of their home supporters.
The defeat piled on more pressure on Benitez, who according to some pundits, will soon get the boot, as his style of coaching and tactics are not really what the owner was hoping for.
West Ham v Chelsea
West Ham: Jaaskelainen, Demel, Collins, Reid, O’Brien, Tomkins, Noble, O’Neil, Nolan, Jarvis, Cole
Subs: Spiegel, Taylor, Diame, Maiga, Spence, Fanimo, Moncur
Chelsea: Cech, Azpilicueta, Ivanovic, Cahill, Cole, Mikel, Ramires, Moses, Hazard, Mata, Torres
Subs: Turnbull, Ferreira, Bertrand, Romeu, Oscar, Marin, Piazon
Referee: Martin Atkinson