West Ham United produced a stunning 3-2 win over Chelsea at the London Stadium on Wednesday.
Mired in a deep relegation battle, Andriy Yarmolenko's 89th minute winner has put the Hammers three points clear of the drop zone.
West Ham had thought they had broken the deadlock through Tomas Soucek in the first-half, only for VAR to rule Michail Antonio offside.
The visitors responded with a penalty from Willian after Christian Pulisic was fouled by Issa Diop.
But there was redemption shortly after for Soucek, the Czech midfielder rising above Cesar Azpilicueta to head home Jarrod Bowen's deep corner.
Bowen then had another assist six minutes after the break when his fizzing low cross was converted from close range by an effervescent Antonio.
Frank Lampard responded by replacing Mateo Kovacic with Mason Mount and bringing on Olivier Giroud for a disappointing Tammy Abraham.
A brilliant free-kick from Willian squared things up, but substitute Yarmolenko had the last laugh when he was sent through on goal by Antonio, who lead the line all game and was clearly man-of-the-match.
The loss means Chelsea missed out on the opportunity to move into third, while also allowing Manchester United and Wolves to remain two points behind them.
Speaking after the game, Hammers boss David Moyes said: "I know Yarmolenko can score. He has a good record. I felt the time was right to make a change. We were up against it at that time at 2-2 but the players stuck at it and we got a result.
"This VAR stuff I am beginning to lose faith with it. I was spewing. I was thinking are we going to get a decision here?
"I feel some of the things that have gone against West Ham recently has been really poor but I said to the players we had to change our luck. The players deserve a massive amount of credit. They are sticking to it.
"What we are asking him [Michail Antonio] to do is a massive job. It would be hard to play with two up top against Chelsea, they always cause you problems when they switch the play. We did a good job, were well organised. Thankfully we have got the three points.
"If you get to 40 you will be safe in the Premier League so we have to aim for that tally. It probably means winning another three games."
