Kalou struck in the 55th minute at Upton Park but it needed Cech tosave Mark Noble's penalty to keep them ahead and send them intoEuropean action in high spirits.
The celebrations for Kalou's goal were marred by objects being thrownin the direction of Frank Lampard and John Terry, although that ishardly likely to affect a Chelsea team that are focused on ending theirseason with silverware.
They started the weekend six points behind Barclays Premier Leagueleaders Manchester United and Guus Hiddink, in charge until the end ofthe season, has given up hope on catching them.
Salomon Kalou's 55th minute goal was all that separated the sides as Chelsea eased past West Ham at Upton Park
West Ham v Chelsea: How the game unfoldedWEST HAM