Eden Hazard gave them the lead after a swift 25th-minute counter-attack before Diego Costa's tap-in shortly after the interval put the Blues in control at West Ham's London Stadium.
West Ham's Manuel Lanzini grabbed a late consolation in injury time, but the result was never in doubt.
London football! Relive the action on Standard Sport's blog.
Can't see the blog! Click here for the desktop version.
West Ham XI: Randolph, Kouyate, Fonte, Reid, Cresswell, Noble, Obiang, Feghouli, Snodgrass, Lanzini, Carroll
Substitutes: Adrian, Collins, Ayew, Byram, Masuaku, Calleri, Fernandes
Chelsea XI: Courtois, Azpilicueta, Luiz, Cahill, Moses, Kante, Fabregas, Alonso, Pedro, Costa, Hazard
Substitutes: Begovic, Zouma, Loftus-Cheek, Willian, Batshuayi, Terry, Matic
Referee: Andre Marriner
WHAT THEY SAID
Slaven Bilic exclusive: "At Chelsea, though, the whole team are playing with that peak energy.
"The best example I can give is [Eden] Hazard. He is working as hard as anyone in that team now.
"Having said all those nice things about [Antonio] Conte and his Chelsea team, I would be so happy it we could ruin their night."
Antonio Conte: "This game against West Ham is very important. In our last away game, Burnley played very physical football against us.
"Maybe the same [1-1 draw] can happen against West Ham, but we have prepared for this situation."