VAR had its biggest moment in Premier League history as Arsenal held on to beat West Ham 1-0 after Callum Wilson's 95th-minute equaliser was ruled out for a foul on David Raya.
Leandro Trossard's late winner set the Gunners on course for a crucial win in the Premier League title race, but with time nearly up Wilson fired home from a corner to send the London Stadium into a frenzy.
However, the VAR spotted the arm of West Ham's Pablo across Raya's neck as the Arsenal goalkeeper fumbled the initial delivery into the box. Referee Chris Kavanagh was sent to the monitor by VAR Darren England and disallowed the goal.
There were two minutes and 35 seconds between the ball crossing the line and Kavanagh being sent to the monitor.
Referee Kavanagh then watched 17 replays of the incident before making his decision. In total, it took 4 minutes and 17 seconds between the ball crossing the line and a foul being awarded.
"I think it's a foul," said Your Site Gary Neville. "He's holding Raya. It is the biggest moment in VAR history in the Premier League."
Had it stood, Wilson's goal would have cut Arsenal's lead at the top to three points - and Manchester City could have returned to the top of the table with a win in their game in hand over Crystal Palace on Wednesday, live on Your Site.
But instead, Arsenal's lead is at five points - and with relegated Burnley at home and a final day visit to Crystal Palace remaining this season - they have taken a big step to a first Premier League title in 22 years.
West Ham, meanwhile, remain in the relegation zone and Tottenham could go four points clear of them if they beat Leeds - who are now safe along with Nottingham Forest and Crystal Palace - live on Your Site' Monday Night Football.
Nuno Espirito Santo: "There is a referee and VAR, there are circumstances in the past that have been judged different. Even the referees don't know what is a foul and what is not a foul, It creates doubt."
Jarrod Bowen: "You can't wipe a goalkeeper out but the keeper has come in to grab the ball and has to expect contact. It's the Premier League; there is going to be contact. If you look at something long enough, you will find something to give."
Mikel Arteta: "It's a call from the refs that I think is very brave, but very consistent with what they've been talking about all season. So when I have to be critical, I have been. And today I have to praise them, at least for giving the option to a referee to decide. When you look at the action in that way, I think it is an obvious error."
Roy Keane: "I think it is a foul. It was really silly from West Ham. Don't make it such an obvious foul because they are going to check."
Ian Wright: "I'm not a fan of VAR but in this instance it did the job. For me it was an easy one to give in such a tense moment."
Jamie Redknapp: "He's got his left arm across his neck. It's a foul."
Leandro Trossard: "Raya said straight away it can't be a goal. At that moment, I had a lot of faith. I believed because he was pretty convincing, but you never know."
It was a tricky afternoon for Arsenal for 83 minutes - mostly due to Mikel Arteta's own doing. After a dominant start which saw Trossard hit the bar twice from the same corner, Riccardo Calafiori go close - it all threatened to unravel after Ben White's injury.
Arteta brought on Martin Zubimendi - moving Declan Rice to right-back. But as West Ham grew into the game, Arteta reversed that decision at half-time - bringing Cristhian Mosquera on to move Rice back into midfield.
Then Arteta took Zubimendi off midway through the second half in another U-turn, that led to West Ham getting even more confidence.
Even though Arsenal had more shots, the disjointed display nearly led to a West Ham opener when Fernandes went through on goal for West Ham in the area. Raya produced his stunning close-range stop - but that was not even his last big action of the game.
Arsenal found a way in their biggest Premier League goal in 22 years. Some excellent interplay with Martin Odegaard saw him enter the penalty area and tee up Trossard who curled in at the near post. The Arsenal away end went bedlam, as Arteta ran down the West Ham touchline.
But there would be more drama to come. A West Ham corner was flapped at by Raya and Wilson smashed home from the loose ball. Then the goal was ruled out - but the talking of this game is far from over.
Arsenal manager Mikel Arteta:
"Probably today I have realised how difficult and how big is the referee's job.
"Because you're talking about a moment that can decide the history, the course, of two massive clubs that they are fighting with their lives to achieve their objectives. And the pressure is huge.
"There are still two games to play. We came to win the game today; somehow, you have to get rewarded.
"You have to have the ability to win in all types of contexts. We have shown that. The only thing that matters is now, the present. Today, we have done it. There are two more to go."
West Ham head coach Nuno Espirito Santo to Your Site:
"Due to the circumstances and the way it finished, we are all upset. Look, there is a referee and VAR, there is circumstances in the past that have been judged different. Let's not go further than that.
"Due to the recent seasons, it has been happening [similar incidents]. Even the referees don't know what is a foul and what is not a foul, It creates doubt.
"Let's look at the game overall. We made a very good match. Arsenal is a tough team. We lost the game."
