West Ham dropped to 16th as a wretched 3-0 defeat to Burnley at Turf Moor condemned them to a sixth game without a win.
Ashley Barnes put the hosts ahead inside 10 minutes from a corner which should not have been awarded but West Ham had reason to feel some justice had been done when Chris Wood's header was then ruled out by a VAR review for a marginal offside.
Their relief was short-lived as a minute before the break Fabian Balbuena's lazy touch from Roberto's throw allowed Dwight McNeil to nip the ball off him, and Wood turned home his square ball with a great finish.
West Ham had not managed a shot on target before the break but rallied in the early stages of the second, only for Roberto to punch Ashley Westwood's corner into his own goal (54).
Burnley: Pope (7), Bardsley (7), Tarkowski (8), Mee (7), Taylor (7), Hendrick (7), Westwood (8), Cork (7), McNeil (8), Wood (8), Barnes (8).
Subs: Rodriguez (n/a), Brady (n/a).
West Ham: Roberto (5), Fredericks (4), Balbuena (3), Diop (5), Cresswell (6), Noble (5), Rice (4), Snodgrass (6), Fornals (5), Anderson (4), Haller (5).
Subs: Yarmolenko (6), Lanzini (5), Ajeti (5).
Man of the match: Dwight McNeil
The visitors totally collapsed after that setback and only avoided further punishment thanks to a combination of some fine Roberto stops and poor Burnley finishing, but that did nothing to sugarcoat a dreadful performance which was compounded by potentially serious injuries to captain Mark Noble and substitute Manuel Lanzini.
Burnley bounce back in style
Going into the international break, both sides were in need of a morale-boosting three points. West Ham had been humbled by Newcastle at the London Stadium last week, while Burnley were soundly beaten 3-0 at Sheffield United.
At kick-off only one side looked up for the fight, and Burnley set about hassling and harrying their visitors from the first whistle.
Burnley changed both full-backs, bringing in Phil Bardsley and Charlie Taylor, while Chris Wood returned in attack.
Pablo Fornals and Ryan Fredericks both earned recalls for West Ham.
But they were handed a huge slice of luck for their opener as referee Kevin Friend wrongly gave Barnes' deflection on Phil Bardsley's long-range effort as a corner, and, from it James Tarkowski headed back across goal for Barnes to poke in from close-range.
It was Burnley's turn to feel aggrieved with the officials next, as McNeil's wonderful cross was met with a bullet header from Wood, but after a VAR review which appeared to surprise a number of players on both sides he was ruled offside by a matter of millimetres.
He would get his redemption within eight minutes. Balbuena's dreadful touch under little pressure invited McNeil to strike and he robbed the defender of the ball before squaring from the left channel, and a confident Wood finish doubled the lead before he celebrated with a tongue-in-cheek mockery of a VAR check.
West Ham finally registered two shots on target in quick succession in the early stages of the second half but neither tested Nick Pope, before they shot themselves in the foot with a dreadful third.
Westwood's corner dipped wickedly above Roberto but the goalkeeper should have done much better than his limp punch into his own net to gift the hosts a third, and, from then on, the Hammers looked devoid of any confidence.
The goalkeeper atoned for his mistake by pulling off a number of fine saves to deny Barnes, Wood and Bardsley, while Andriy Yarmolenko fired wide from a fine position at the other end as the match reached its conclusion.
What the managers said
Burnley manager Sean Dyche: "It was a really good reaction, we made some changes. It's tough making changes because we've got a good group and you can only play 11.
"We spoke before the game, winning your one-on-ones, that's an important factor in the psychology of the game. Our body language was good from the start, and if you get all those simple things right you've got a chance.
"There's a lot to be pleased about, we knew we were coming up into a tough run and we've got six points from the last five games, which doesn't look like a lot but when you look at the opposition we've played it's not that bad."
West Ham boss Manuel Pellegrini: "I don't know if it was unacceptable, but there were big mistakes for the goals. The first goal a set-piece, it was a corner which was not a corner, but we must defend it anyway, and then two very big mistakes.
"Of course, it is a concern how the performances have dipped. It's a very difficult moment, but you have to perform as a team. In this moment we have a lot of poor performances from a lot of players and now we are trying to recover, not only the results but the trust too."
Man of the match - Dwight McNeil
It was difficult to narrow down Burnley's wonderful performance to pick out one individual. Sean Dyche mentioned the word team repeatedly in his post-match press conference and it was a game where the whole was greater than the sum of its parts, as it always is when Burnley are at their best.
But McNeil's wonderful crossing deserves its own mention. VAR ruled out an incredible first-half assist but even that could not deny him at the second attempt, and Wood should have made it four from another fine delivery only to hoof over at the near post.
- West Ham have lost four of their last five Premier League games (D1), after suffering just one defeat in the 11 before that.
- Chris Wood has scored in all five of his Premier League games against West Ham, the best 100% scoring record against an opponent in the competition's history.
- Burnley youngster Dwight McNeil (4) is one of just three teenagers to assist at least four goals in Europe's big five leagues this season, alongside Borussia Dortmund's Jadon Sancho (5) and Parma's Dejan Kulusevski (5).
After the international break, Burnley's next game comes sees Sean Dyche head back to former club Watford on November 23 at 3pm. There is a London derby for West Ham who host Tottenham in the 12.30pm kick-off earlier that day.