A goal down after 10 minutes, a man down after a further six, Chelsea produced the football of champions to move significantly closer to back-to-back titles.
Although Manchester United maintained their challenge with the impressive dispatch of Arsenal four hours later Chelsea will now feel they are on the home straight. They still have some tricky-looking fixtures remaining but the manner of this victory will give them renewed confidence. It should also ease the siege mentality which had taken hold and quell the doubts about Jose Mourinho's management style.
Three wins from their remaining five games will now be enough to retain the Premiership and if Chelsea take maximum points from their brace of Easter fixtures they can do so by drawing with their nearest pursuers at Stamford Bridge on 29 April. Should United falter it could be over before then.
Didier Drogba, looking every inch the complete centre-forward, and never once losing his feet unnecessarily, led Chelsea's reply to an opening passage of play which tested their mood and character. After careless defending allowed James Collins to head West Ham in front Chelsea were reduced to 10 men for the sixth time in 2006. This time Maniche went, for a reckless challenge on Lionel Scaloni. With Mourinho's team selection - which featured four central midfielders, two centre-forwards, and no wide players - already having encouraged speculation as to his state of mind, there seemed a real prospect of Chelsea imploding.
No one doubted that the likes of John Terry and Frank Lampard would rise to the challenge. Less expected was the way that Drogba rose to the task. This was the Drogba who carried the Ivory Coast to the World Cup finals, not the one with the footwork of Bambi on ice.
He bullied West Ham's hapless defence into submission, especially Scaloni and Collins whose joy at scoring soon dissipated. Collins had beaten Asier del Horno and Maniche to Yossi Benayoun's corner to head in, but he rarely beat Drogba to the ball.
Chelsea nearly levelled immediately. Only a last-ditch clearance by Danny Gabbidon prevented Hernan Crespo converting a cross from Del Horno. Then Maniche, from Drogba's cut-back, struck the bar, with Michael Essien heading the rebound wide of a gaping goal. Then Maniche lunged at a loose ball, going over the top and into Scaloni. Mourinho, lapsing into unworthy paranoia even in victory, said that there was a "strange smell" about the dismissal but, while Scaloni exaggerated, the tackle was undeniably reckless. For a while West Ham seemed in control, passing the ball around to stretch and tire the 10 men.
Then Lampard clipped a first-time blind pass over the top from his own half. Drogba accelerated off the shoulder of Collins and scored at the second attempt. Two minutes later Gabbidon's poor clearance was fed to Drogba whose shot deflected off Collins across goal. Scaloni, seemingly unaware that Crespo, a £17m predator, was behind him, let the ball run allowing the Argentinian to score.
From then on there was only one team in it. When the linesman later broke his flag, prompting a hunt for a replacement yellow one, the thought occurred that he could have borrowed the white flag that the visiting team had raised. As Mourinho said: "We played with 10 but it looked like we played with 12."
The points only remained in doubt until the break because Shaka Hislop made an alert save to deny Drogba after Collins misjudged Geremi's cross. Any uncertainty was erased after 53 minutes when Terry volleyed home after Gallas hit the bar at a corner. Gallas, enjoying a rare outing at central defence, tapped in himself after Arjen Robben's free-kick had caused chaos.
There were still 22 minutes left but Chelsea declared at four. In the event it was the visitors who came closest to scoring, Gallas clearing Teddy Sheringham's 87th-minute shot off the line. The contest was long over then. So, on this form, will soon be the championship race.
Goals: Collins (10) 0-1; Drogba (28) 1-1; Crespo (31) 2-1; Terry (54) 3-1; Gallas (69) 4-1.
Chelsea (4-1-2-1-2): Cech; Geremi, Gallas, Terry, Del Horno; Makelele; Essien (Carvalho, 89), Lampard; Maniche; Crespo (Robben, 66), Drogba (J Cole, 89). Substitutes not used: Cudicini (gk), Wright-Phillips.
West Ham United (4-1-4-1): Hislop; Scaloni, Collins, Gabbidon, Konchesky; Mullins; Harewood, Benayoun (Sheringham, 72), Reo-Coker, Etherington; Ashton (Zamora, 84). Substitutes not used: Walker (gk), Newton, Clarke.
Referee: C Foy (Merseyside).
Booked: West Ham United Harewood, Konchesky.
Sent off: Chelsea Maniche (16).
Man of the match: Drogba.
The power of 10: Three great comebacks by depleted teams
* TOTTENHAM 3 MANCHESTER CITY 4 (4 Feb 2004 FA Cup 4th round replay)
City were three down when Joey Barton was sent off on the stroke of half-time. But Jon Macken capped an extraordinary comeback with a 90th-minute winner.
* MANCHESTER UTD 1 EVERTON 0 (18 May 1985, FA Cup final)
Kevin Moran made history as the first player to see red in a Cup final, but Norman Whiteside made up for that by curling a left-footed shot past Neville Southall in extra time.
* LIVERPOOL 3 EVERTON 1 (25 March 2006 Premiership)
Liverpool were up against it when the captain Steven Gerrard was sent off after only 18 minutes but they had the game won long before Andy van der Meyde also saw red late on.Reuse content