The Hammers grabbed all three points thanks to Cresswell strike and David Martin clean sheet on debut
Chelsea 0 West Ham United 1
Manuel Pellegrini will sleep much easier tonight after his new-look Hammers ended a win-less eight-match run with this fantastic, hard-fought victory over high-flying Chelsea at Stamford Bridge.
Aaron Cresswell's 48th-minute winner provided the unexpected lift that the whole of the East End needed but this was a team performance to be cherished all the way from debutant goalkeeper David Martin, through defiant defence and industrious midfield to exhausted striker, Michail Antonio.
Indeed, the selection of Martin - offspring of on-looking Hammers legend, Alvin - meant that the debutant 'keeper and his Dad now became the eighth father and son combination to represent the Hammers, as they followed in the footsteps of the families Barrett, Lansdowne, Brown, Lampard, Potts, Lee and Moncur.
The 33-year-old with over 400 career appearances between the sticks, came in for under-fire Roberto, who dropped to the bench alongside record-signing Sébastien Haller and Andriy Yarmolenko as Pellegrini made a quartet of changes from the side that had lost so disappointingly to Tottenham Hotspur, last Saturday.
With Issa Diop also suspended, the Chilean - looking to arrest an alarming loss of form - also recalled lone-attacker Antonio, Fabián Balbuena and Pablo Fornals to a West Ham team kicking-off in 17th-spot, both 13 places and 13 points behind Lampard's Blues.
Felipe Anderson also moved into a more central attacking role as the Hammers got off to a lively determined start with Antonio soon prodding Cresswell's left-wing cross over the bar from ten yards, while at the other end, the new man in the gloves enjoyed vociferous chants of 'One David Martin' from the visiting supporters as he held Reece James' routine cross before getting his body behind Mason Mount's low 18-yarder.
Chelsea had shared a 2-2 draw in Valencia on Wednesday evening and switching from the Champions League to the Premier League, Lampard made five changes as Mount, Pedro, Emerson, Olivier Giroud and Fikayo Timori each came in for injured top-scorer Tammy Abraham (hip) plus substitutes N'Golo Kanté, Andreas Christensen, Willian and César Azpilicueta.
On the quarter-hour mark, Martin also plucked Christian Pulisic's low cross off Pedro's studs as the Blues gradually got into their stride and James' deflected right-wing cross deceived everyone as it looped onto the outside of the near post, before Kurt Zouma then glanced the consequent corner inches wide of the far upright.
Midway through the half, though, it was the Hammers who almost broke the deadlock when Robert Snodgrass whipped the perfect right-wing centre into the danger-zone where Antonio's flying header was acrobatically beaten away at full stretch by Kepa Arrizabalaga.
Then just before the break, Martin parried Mateo Kovacic's low 20-yarder before denying both Giroud and Pedro as they desperately tried turn home the loose ball, albeit a raised offside flag would probably have wiped those latter two efforts and, right on the stroke of half-time, Pulisic skied over at the far post to keep it goalless at the interval.
Just three minutes into the second period, though, the Hammers decisively drew first blood.
Midway inside the Chelsea half, Snodgrass played the ball in-field to Anderson, who quickly found the supporting Fornals on the left side of the Blues area and the fast-thinking Spaniard played in Cresswell, who easily turned James before curling a right-footed 12-yarder beyond the outstretched left glove of Arrizabalaga and inside the right-hand upright.
The ecstatic East Enders packed behind the Spanish 'keeper's net went wild way out West as the three-times capped England defender celebrated his third goal of the season and, they were nearly cheering again, when Balbuena met a Snodgrass corner with a thumping header that Arrizabalaga turned aside.
The consequent flag-kick again saw Balbuena send another nodded effort goalwards but Antonio just could not get the vital touch on the line and, having survived that scare, Lampard introduced Willian and Kanté the expense of Pedro and Jorginho.
After Fornals had been booked for checking James, the Hammers looked to have doubled their lead when Snodgrass whipped a right-wing cross to the far post where Antonio forced the ball between Zouma and Timori at the second attempt but the dreaded Video Assistant Referee overturned the effort for handball.
Yarmolenko - who would later be booked for chopping Emerson - then replaced an angry Anderson for the final 20 minutes, while Callum Hudson-Odoi came on for Giroud and Haller stepped from the bench to take over from Antonio who had, understandably run out of gas on his first start since late-August.
Heading into the closing minutes Arthur Masuaku arrived to help quell the potential threat of Willian as Fornals retired but soaking up endless Blues pressure in a frantic finale, the Hammers held out to end a win-less run of 13 visits to Stamford Bridge - where they had not won in the Premier League since 2002 - while their heroic 'keeper left to yet more deserved chants of 'One David Martin'.
BLUES: Arrizabalaga, James, Emerson, Zouma, Timori, Jorginho (Kanté 62),, Mount, Kovacic, Pedro (Willian 62), Pulisic, Giroud (Hudson-Odoi 70). Unused subs: Caballero, Christensen, Batshuayi, Azpilicueta.
HAMMERS: Martin, Fredericks, Cresswell, Balbuena, Ogbonna, Rice, Noble, Fornals (Masuaku 82), Snodgrass, Anderson (Yarmolenko 70), Antonio (Haller 75). Unused subs: Roberto, Zabaleta, Sánchez, Ajeti
Booked: Fornals (64), Yarmolenko (88), Cresswell (90+2)
Referee: Jonathan Moss
Attendance: 40,595.
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