Swansea City ensured West Ham's penultimate fixture at the Boleyn Ground ended in defeat following a thrilling 4-1 triumph in East London.
The Swans, who made six changes for their final away Premier League fixture of the season, earned a deserved three points, thanks to goals from Wayne Routledge, Andre Ayew, Ki Sung-Yueng and Bafe Gomis.
Despite a bright start from the hosts, the Swans took the lead inside 25 minutes when Routledge tapped home from close range following a fine flowing move by the visitors.
Ayew then doubled Swansea's advantage after the half-hour mark when he met Stephen Kingsley's inviting cross from the left flank to prod into the back of the West Ham net.
After the interval, Ki Sung-Yueng volleyed home Swansea's third of the afternoon, guiding the ball into the bottom corner from Modou Barrow's cross.
Second-half substitute Diafra Sakho pulled one back for the Hammers in the 67th minute, but Swans sub Bafe Gomis restored Swansea's three-goal cushion on the brink of full-time.
The three points moves the Swans up to 11th in the Premier League and onto 46 points for the season.
Francesco Guidolin makes six changes to the starting line-up for today’s Premier League clash at the Boleyn Ground.
Kyle Naughton, Federico Fernandez and Stephen Kingsley all come into the back four as Angel Rangel, Ashley Williams and Neil Taylor miss out - with Williams being rested and Taylor nursing a groin problem.
Meanwhile, in midfield, Leroy Fer returns after missing the win over Liverpool with a hamstring injury, and Ki Sung-Yueng also starts as Leon Britton moves to the substitutes bench and Gylfi Sigurdsson misses out with a shoulder injury.
Finally, Modou Barrow gets the nod on the flank as Jefferson Montero is ruled out with a hamstring problem, while Jack Cork captains the Swans in the absence of Ashley Williams.
West Ham, meanwhile, make two changes to their starting line-up with Slaven Bilic’s side harbouring hopes of qualifying for Europe.
WEST HAM: Darren Randolph, Michail Antonio, Winston Reid, Angelo Ogbonna, Aaron Cresswell, Cheikou Kouyate (Emmanuel Emenike, 77), Dimitri Payet, Victor Moses (Diafra Sakho, 59), Mark Noble (capt), Manuel Lanzini (Enner Valencia, 84), Andy Carroll.
SUBS: Raphael Spiegel, James Tomkins, Pedro Obiang, James Collins.
SWANS: Lukasz Fabianski, Kyle Naughton, Federico Fernandez, Jordi Amat, Stephen Kingsley, Ki Sung-Yueng, Jack Cork (capt), Leroy Fer, Wayne Routledge (Bafe Gomis, 82), Modou Barrow (Angel Rangel, 69), Andre Ayew (Leon Britton, 90+4).
SUBS: Kristoffer Nordfeldt, Jay Fulton, Kenji Gorre, Marvin Emnes.
West Ham dominated possession and territory during the opening exchanges and had chances to take an early lead.
Inside two minutes, Dimitri Payet had Lukasz Fabianski stretching at full length to turn the Frenchman’s swerving effort around the post, before Winston Reid’s header from the resultant corner was well held by the Polish goalkeeper.
The Swans looked to threaten on the counter-attack and were not without their opportunities to test West Ham stopper Darren Randolph.
After squandering several good attacking positions on the break, the Swans took the lead when Wayne Routledge opened the scoring in the 25th minute.
The winger tapped home from close range following a fine move by the visitors, which was capped off by a superb volley-cross from Kyle Naughton to play in Routledge from the right.
West Ham then saw a glorious chance go begging when Angelo Ogbonna blazed over from inside the box after the ball had dropped kindly for him, while, at the other end, Ki Sung-Yueng's free header was comfortably saved by Randolph.
But the visiting Jack Army were on their feet again when Stephen Kingsley surged down the left flank before fizzing a ball across the six-yard box for Andre Ayew to fire home Swansea's second just after the half-hour mark.
And it could have so easily been 3-0 to the Swans just moments later when the ball fell loose to Routledge in the box, whose fiercely struck effort was well blocked by Ogbonna.
Shortly before the interval, Modou Barrow had a chance to extend Swansea’s lead after he was played through by Routledge, but the flying winger dragged his shot wide of the target.
West Ham, meanwhile, should have clawed one back on the cusp of the interval when Michail Antonio's flashed a ball across Fabianski's six-yard box, but neither Andy Carroll or Manuel Lanzini could convert from close range.
HALF-TIME: West Ham 0-2 Swans
The Swans picked up from where they left off after the break as Ki volleyed home Swansea’s third of the afternoon, six minutes into the second period.
The South Korea international caressed the ball into the bottom corner after Barrow showed great skill and an even better delivery into the box from the left flank.
But the hosts were intent on not bringing the curtain down on their time at the Boleyn Ground on a sour note, with Fabianski the obstacle preventing them from finding a way back into the game.
Fabianski did superbly to parry Antonio's powerful effort from 12 yards, before Carroll's follow up flew narrowly wide of the target.
But Fabianski's resistance was finally broken in the 67th minute, despite having made another superb double save to deny Antonio and substitute Diafra Sakho. On this occasion, however, Sakho was able to find the back of the net with the rebound from point-blank range.
With 20 minutes left on the clock, West Ham continued to press for a second as Sakho again went close for the hosts, only to be blocked at the last moment by Federico Fernandez.
The Swans managed to weather West Ham's second wind, and substitute Bafe Gomis could have restored Swansea's three-goal lead just minutes after his introduction, only to see his first effort on goal tipped on to the top of the crossbar by Randolph.
But Gomis made no mistake with his second attempt as the Swans broke clear from West Ham's corner. Following a neat exchange with Ayew, the French striker calmly slotted home into an empty net to all but secure the three points for Francesco Guidolin's side.