Andre Ayew headed a second-half winner as West Ham gatecrashed Burnley's party by snatching a 2-1 victory at Turf Moor.
Already assured of Premier League survival and their highest finish since 1975, the Clarets were in the mood to celebrate on the final day and Sam Vokes enlivened the atmosphere further by putting them ahead.
But Sofiane Feghouli responded with a quick leveller and, after Sean Dyche's men wasted several chances to reclaim the lead, Ayew punished the hosts by pouncing on a rebound after 72 minutes.
It made for a slightly disappointing end to the season for Burnley, who had claimed 10 of their 11 wins at home, but the appreciation of their fans for a fine effort was not tainted.
Enthusiasm got the better of a number of supporters as they ran on to the pitch at the final whistle, delaying the team's planned lap of appreciation, but the area was cleared by stewards.
They can still look ahead to next season in good heart while West Ham, despite the result, must take stock after a campaign in which they have slipped back.
Burnley started well and almost grabbed the lead in the first minute after James Collins misjudged a bouncing ball, but Andre Gray snatched at the chance.
West Ham also threatened in a lively start to the game, but Tom Heaton was equal to the impressive Feghouli's well-struck shot.
Burnley pressed again but Vokes failed to make a clean connection after being picked out in front of goal by Robbie Brady and James Tarkowski headed over from a corner.
Their reward came in the 23rd minute when Gray whipped in a low cross and Vokes made no mistake from close range after Jeff Hendrick failed to make contact.
The lead lastest just four minutes, however, as West Ham responded with a neat move which saw Ayew flick the ball into the path of Feghouli and the Algerian drilled a low shot past Heaton.
Feghouli might have had another soon after but blasted over, while Gray missed a good chance to restore the Clarets' lead just before half-time when he backheeled narrowly wide from Brady's cross.
Vokes glanced a header wide early in the second half before Hendrick sent a free-kick well over the bar and Ashley Westwood miscued a volley.
The Clarets were made to pay for failing to make the most of their dominance as the visitors grabbed the lead 18 minutes from time.
Heaton did his best to repel danger as he palmed away a fierce shot from Edimilson Fernandes but the ball looped upwards, fell on to the bar and then bounced out kindly for Ayew to head home.
The celebrations in the away end got a little out of hand as a flare was thrown on to the pitch, delaying the restart.
The intensity was lost after that and the game, and the season, drew to a gentle conclusion.