Goals in either half from Andy Carroll and Stewart Downing sealed the points for Sam Allardyce’s men and confirmed Nigel Pearson’s side would occupy bottom spot in the Premier League on Christmas Day.
Carroll capitalised on Paul Konchesky’s backpass midway through the first half to hand the hosts the lead just moments after he missed a glorious opportunity to break the deadlock.
The hosts rarely threatened to get on the scoresheet and were dealt a blow 10 minutes after interval as Downing collected Diafra Sakho’s knock-down from a long ball to curl exquisitely past Ben Hamer in the Leicester goal.
Substitutes David Nugent and Leonardo Ulloa saw late attempts expertly saved by Hammers keeper Adrian in the closing stages, but a comeback did not materialise as West Ham ensured they would be in the top four over the Christmas.??
The Hammers have made their best Premier League start and now have an eye on Europe while Leicester must dig deep to have any hope of survival.
The hosts set about imposing their physical and, at times, aerial game on the visitors from the offset.
Kouyate found some space down the right wing and, after evading Konchesky down the left, floated a ball deep to the far post where Andy Carroll looked to exert his strength, but nothing came of the opening.
Leicester boss Pearson then watched Jamie Vardy’s dangerous cross into the six-yard box evade everyone and his side fail to capitalise on Adrian’s throw straight to Esteban Cambiasso.
Sakho should have given West Ham the lead but was unable to direct his first-time volley on target. But it was to be his strike partner who spurned a far easier chance when Carroll, after receiveing the ball from Downing, blasted over from six yards out.
The striker quickly made amends as within two minutes the deadlock was broken. Former Hammer Konchesky aimlessly passed back to Hamer without looking and Carroll pounced to deftly finish over the on-rushing keeper.
Carroll was unable to connect with an acrobatic effort early in the second half and there was a moment of alarm when he appeared to jar his ankle and knee in an innocuous incident before he crashed into the advertisement hoarding and a photographer or two.
But Carroll brushed himself down and was involved in the game’s deciding goal. As West Ham reverted back to the classic route-one play, the striker made a nusciance of himself in the Leicester ranks and allowed Sakho to flick the ball into the path of Downing, who curled home an excellent astrike to all but seal the points.
Nugent and Ulloa were denied by Adrian at point-blank range late on as Leicester rallied. Had either header gone in it would have set up a grandstand finsh, but as it was the Hammers eased to victory.
West Ham: Adrian (7), Jenkinson (6), Tomkins (6), Reid (6), Cresswell (7), Nolan (5), Song (), Kouyate (6), Downing (7), Sakho (6), Carroll (8).
Used subs: Collins (5), Amalfitano (4), Valencia (5).
Leicester City: Hamer (5), Simpson (4), Wasilewski (5), Morgan (5), Konchesky (3), Mahrez (6), King (6), Cambiasso (4), Drinkwater (5), Schlupp (6), Vardy (6).
Used subs: Ulloa (5), Knockaert (4), Nugent (5).
Man of the Match: Andy Carroll.