The Belgium international slalomed past several players to score a brilliant opener midway through the first half and killed off the visitors' resistance in the 90th minute as Maurizio Sarri's men strengthened their aspirations of Champions League qualification.
Chelsea were especially captivating throughout the opening 45 minutes and now sit above Tottenham and Arsenal, though both teams have a game in hand.The Blues' triumph served as a significant boost at the outset of a busy period that takes them to Slavia Prague for the first leg of their Europa League quarter-final tie on Thursday.
Sarri named Callum Hudson-Odoi in the starting line-up for the second game in succession, but it was star man Hazard who made the first, dazzling incision.
The attacker skipped past multiple challenges as he sliced through the heart of West Ham's defence and fired into the bottom-right corner in the 24th minute.
Gonzalo Higuain twice threatened to double the margin before the break, rattling the near post with one effort and forcing Ryan Fredericks into an important block with another.
The Hammers established more of a foothold after the interval. The fit-again Felipe Anderson tested Kepa Arrizabalaga before Aaron Cresswell thumped marginally wide as Chelsea's lead began to appear vulnerable.
One man stood a class above the rest, though, and an unmarked Hazard fittingly put the seal on his side's third consecutive victory, receiving substitute Ross Barkley's pass into the box and lashing an unerring finish across Lukasz Fabianski.
Hazard still the star of Stamford Bridge
Reports that Real Madrid are set to step up their interest in Hazard have clearly done nothing to affect the 28-year-old's focus on the task at hand.
He was at his scintillating best in this match, pulling West Ham's defence from side to side and landing the knockout blows with typical class.
