This was no smash and grab win for the Hammers as they won 1-0 at Stamford Bridge this afternoon.
Chelsea were terrible, especially in the second half, but the visitors from the other end of the District line were worthy victors.
Did the events in Valencia take their toll in terms of match freshness - where the Blues drew 2-2 in a tight Champions League encounter ? It’s a bit of a cliched excuse but there might be a touch of truth to it.
But despite that, West Ham has a game-plan to thwart, pester and defend deep.
They also had a goal disallowed by VAR - so no real excuses.
Did the fact that the Blues are at home in the league to Aston Villa on Wednesday have a factor in Frank Lampard’s decision on team selection. He would probably say no.
But it was West Ham's first win at the Bridge in 17 years.
On this performance, it won’t be their last.
Pedro had the first chance of the game, slicing a left-footer from an Emerson byline cross, goal-bound.
But the shot was blocked by West Bam’s Fabian Balbuena and the ball was cleared.
West Ham crafted an excellent chance on seven minutes - Aaron Cresswell’s cross was met by Michail Antonia, but the challenge by FIkayo Tomori saw the ball flick into the arms of Kepa.
Hold efforts by Mason Mount and Christian Pulisic quickly followed as the game opened up to a sequence of ‘you shoot, we shoot’.
But it settled down to the Blues dominating possession and the visitors defending deep.
Reece James saw a defected cross crack David Martin’s near post for a corner, on 23 minutes, Kurt Zouma missed a headed sitter from the resultant kick.
After another giveaway ball by Jorginho on 24 minutes, West Ham counter-attacked well and Antonio’s powerful header was brilliantly parried away by Kepa.
The game then entered a fallow period, where neither side looked capable of producing a goal-worthy effort. When Chelsea did on 42 minutes, Olivier Giroud was offside.
Giroud missed another sitter on the stroke of half-time.
There were no changes by either side at half time.
But with the first attempt of the half, the Hammers took the lead - in the simplest of fashion.
A three-man move involving Felipe Anderson, Pablo Fornals and ultimately Cresswell, saw the left back cut James apart before curling a wonderful right-footed curler beyond the desperate dive of Kepa.
It could have been two for the Hammers but Kepa thwarted Fabian Balbuena with a fine diving save, while Antonio could not get to the ball three yards out.
Head Coach Frank Lampard, in an attempt to arrest a steep decline in performance decided to replace Pedro and Jorginho, on came Willian and N’Golo Kante on 63 minutes.
But it made no difference as the home side appeared to go 2-0 down when Antonio bundled the ball home. But VAR intervened as a hand ball was detected and the goal chalked off.
Lampard then brought on Callum Hudson-Odoi for Giroud.
That substitution was a bit of a mystery as striker Michy Batshuayi was kept on the bench.
A late rally by Chelsea would be an understatement - Pulisic had a shot - but it was well wide of gol.
Teams: Kepa, Jorginho, Pedro, Zouma, Kovacic, Giroud, Mount, Pulisic, James, Tomori, Emerson
Subs: Caballero, Christensen, Kante, Willian, Hudson-`Odoi, Batshuayi, Azpilicueta
West Ham: Martin, Cresswell, Balbuena, Anderson, Snodgrass, Noble, Fornals, Ogbonna, Fredericks, Antonio, Rice
Subs: Jimenez, Zabaleta, Yarmolenko, Sanchez, Haller, Masuaku
Referee: Jonathan Moss