Goals by Michael Carrick and Fredi Kanoute in the first 12 minutes set Glenn Roeder's side on their way and although Jimmy Floyd Hasselbaink pulled one back on 22 minutes, West Ham fought like lions to secure all three points that see them climb three places into 13th position.
There were heroes in claret and blue all over the park. Tomas Repka signed off before his suspension with another superb performance at the heart of the back four, Kanoute led the line well and worked harder than ever up front, while Don Hutchison produced probably his most effective display since returning.
Trevor Sinclair hardly played like a man who wants to jump ship with another gritty performance that included setting up both goals, linking up well with Paolo Di Canio on both occasions. The Italian had a quiet night by his own standards.
But the man who perhaps deserved most plaudits at the end of an absorbing, high quality game wore green - goalkeeper Shaka Hislop, who put some personal nightmares behind him to make a terrific match-winning save to deny Hasselbaink what looked a certain equaliser with just five minutes of normal time left.
After Saturday's relatively comfortable 2-0 win here over Southampton, this was always going to be a much bigger test for both Roeder and his players - but they were more than up to the task.
Indeed, Roeder effectively scored a tactical victory over Claudio Ranieri by stunning Chelsea with an early blast from which they never quite recovered. West Ham caused the yellow-shirted Blues more problems by playing with greater width in the first half and although Chelsea gained more possession in the 20 minutes before half-time, Roeder refused to go onto the back foot.
Instead, he sent on another striker - young Jermain Defoe - for left midfielder Laurent Courtois at half-time and asked Di Canio to play behind him and Kanoute in a new front three. The switch immediately led to a string of good chances, with Defoe and Di Canio both going close soon after the break.
Inevitably, Hammers had to defend deep for long periods but they didn't crack under pressure in a performance that was so far removed from those awful recent showings at Everton and Blackburn.
Apart from a bad headed miss by Manu Petit in the first minute, Hasselbaink's shot that Hislop saved and another sizzling shot from the Dutchman that rapped the outside of the post in the dying minutes, Chelsea were largely limited to half-chances.
The crowd came ready to let Frank Lampard know what they thought about the manner of his defection and the former Hammer was forced to endure some understandable jeering from the home crowd with their taunts of 'What a waste of money!'. It's hard to say how much of an effect this had on the £11m man but he faded badly in the second half, having missed a very good chance to make it 2-2 when he stole in unmarked near the end of the first half but could only direct his first-time shot at the legs of Hislop.
The night ended early for Lampard, substituted to loud boos 10 minutes from time, and as he and his new team-mates left the field they had ' Bubbles' ringing in their ears.
Home sweet home!
Minute-by-minute:
1 - After Winterburn misjudges Le Saux's cross, Zola's centre is headed over the bar by Petit from six yards out.
4 - Sinclair's low cross is brilliantly dummied by Di Canio but Melchiot blocks Di Canio's effort.
5 - GOAL! Di Canio finds Sinclair with his back to goal on the edge of the area and he in turn lays a short pass to the onrushing Carrick, who places his shot beautifully past Bosnich and in off the post. West Ham United 1 Chelsea 0.
6 - Kanoute's flick on releases Hutchison, who chests down well but fires a left-footed volley just over the bar.
12 - GOAL! Di Canio and Sinclair once again combine to deadly effect and the ball reaches Kanoute on the edge of the area. The Frenchman sidesteps two challenges before turning and firing low past Bosnich. West Ham 2 Chelsea 0.
18 - Hutchison's excellent pass sets Di Canio away on the right, but the Italian's deep cross drops out for a goal kick.
22 - GOAL. Zola's pass releases Hasselbaink on the right and the Dutch striker gets away from Dailly before firing a fierce low shot past Hislop. West Ham 2 Chelsea 1.
29 - Hasselbaink finds space to square a pass to Gudjohnsen, whose low shot from the edge of the area is comfortably held by Hislop.
32 - Sinclair finds Di Canio on the right and the Italian turns Le Saux before whipping in a cross that just skims the head of Kanoute.
38 - Hasselbaink finds Zola, who wriggles free on the edge of the area and fires a left-footed shot high and wide.
40 - Zola's deep cross sails over the head of Winterburn and drops perfectly at the feet of Lampard, whose half-volley is somehow kept out by the legs of Hislop. West Ham immediately break and Sinclair's cross-field pass finds Courtois, who hits a 30-yard effort that just clears the crossbar.
42 - Lampard's turn and shot from the edge of the box is deflected just pass the post for a corner.
Added-time: 1 minute.
45 - Di Canio's quick free-kick releases Courtois on the left, but the Frenchman's low cross is gathered by Bosnich.
Half-time: West Ham 2 Chelsea 1.
Second half:
46 - Substitution for West Ham, Defoe replaces Courtois.
48 - Kanoute's first time flick on releases Defoe, but the young striker clips the ball past the far post with only his second touch of the match.
54 - Di Canio brilliantly skips between Lampard and Melchiot on the left but then takes an extra touch and appears to lose possession. In an instant, he turns back inside and fires in a low shot that Bosnich just manages to hold.
58 - Gudjohnsen dribbles in from the right and turns Dailly before firing in a shot that is deflected for a corner.
61 - Substitution for Chelsea, Dalla Bona replaces Petit.
64 - Hutchison hassles Jokanovic, who loses possession. Defoe picks up the lose ball and feeds Kanoute, who scuffs his shot just wide of the post.
68 - From Di Canio's deep corner, Kanoute heads just inches past the post.
69 - This time it's Hasselbaink's turn to head wide from a corner, provided by Zola.
71 - Substitution for Chelsea, Zenden replaces Gudjohnsen.
76 - Hislop completely misses Zola's corner but Melchiot's effort is thankfully blocked by Hutchison.
80 - Substitution for West Ham, Kitson replaces Kanoute. Substitution for Chelsea, Forssell replaces Lampard.
84 - Zenden releases Hasselbaink on the right and the Dutchman's blistering shot appears to be heading for the bottom corner until Hislop magnificently palms the ball away.
85 - Hasselbaink goes even closer as a loose ball drops to him 12 yards out and he fires in a shot that rattles the outside of the post.
Added time: 3 minutes.
Full-time: West Ham United 2 Chelsea 1.