Burnley twice fought back from a goal down, but ultimately fell to defeat against West Ham at the London Stadium.
Sean Dyche made two changes, one enforced, as Ashley Westwood came in for the injured Jack Cork, while Aaron Lennon replaced Robbie Brady.
But the Clarets got off to a disatrous start as, 10 minutes in, James Tarkowski was too casual in possession and made a hash of his back pass to Joe Hart, and Marko Arnautovic's eyes lit up, the Austrian advancing and slotting inside the near post.
Former Hammer Hart then came to the rescue as Filipe Anderson played in Arnautovic, and stayed big to come out on top in a one on one.
Burnley were their own worst enemies defensively, and offered little in an attacking sense, although skipper Ben Mee was denied an equaliser as Lukasz Fabianski was forced into a diving save to turn away his header from a Johann Berg Gudmundsson corner.
And at the other end, Mee again used his head to make a remarkabkle intervention to deny Anderson a certain second, somehow clearing a curler from just under the bar, with Hart beaten.
Steven Defour was fortunate not to concede a penalty, as he got the faintest of touches, if any, on the ball as Grady Diangana burst into the box, with Anderson booked for his protests.
And out of nothing, right on half-time, Burnley stunned the Hammers as they levelled out of nothing.
Westwood picked out the run of Gudmundsson, who bore down on Fabianski and clipped a finish inside the far post.
There was still time for Hart to dive to his left to save from Pedro Obiang, and Burnley could scarcely believe their luck as they went in level.
West Ham continued on the front foot after the break, and Snodgrass forced a save from Hart, although it needed a fine challenge from the covering Declan Rice to stop Matej Vydra driving goalwards after fine hold up play from Sam Vokes.
Hart beat away an audacious effort from Arnautovic, and as the game opened up, West Ham regained the lead on the break.
Tarkowski clattered Diangana late in the build up, but Roger East played a good advantage and Anderson slotted past Hart and the retreating Mee.
Tarkowski was fortunate to only receive a yellow card in the aftermatch.
However, Dyche responded by bringing on Chris Wood, Ashley Barnes and Robbie Brady, and from a Brady corner, Wood showed real aggression and desire to thump in an equaliser.
Still West Ham came forward, and Anderson shaped an effort against the outside of the far post, before the Brazilian netted the winner, forcing the ball home via a deflection to make it 3-2 after good play from Arnautovic.
And substitute Javier Hernandez sealed the points, collecting Michail Antonio's chest down from a glorious raking pass from Anderson, before firing into the roof of the net.