West Ham were left furious by VAR calls as the Hammers suffered a crucial 2-1 defeat at the hands of Nottingham Forest at the London Stadium on Tuesday evening.
The victory, secured by Morgan Gibbs-White, who converted a penalty in the 89th minute, now provides Sean Dyche's side with valuable breathing room, opening up a seven-point cushion above the drop zone.
For West Ham, the defeat compounds their relegation fears, leaving them stranded seven points from safety.
The result marks a significant moment in Forest's battle for survival following a turbulent campaign that has seen three different managers take charge.
Despite the win, Forest recognise substantial work remains to guarantee their Premier League status.
West Ham took the lead through an unfortunate own goal from Murillo, despite Forest dominating proceedings in the opening period.
Neco Williams forced Alphonse Areola into an excellent save with a strike from 20 yards, while Callum Hudson-Odoi rattled the crossbar with the goalkeeper beaten.
Nicolas Dominguez restored parity within 10 minutes of the restart, before Gibbs-White held his nerve from the spot to clinch all three points.
Nuno blamed two controversial VAR decisions for leaving West Ham staring down the barrel of relegation from the Premier League
|PA
The season has proved since Nuno Espirito Santo guided Forest to seventh place last term, their best finish in three decades.
His September departure preceded Ange Postecoglou's brief 39-day spell, with Dyche becoming their third manager this campaign.
Following the match, Nuno blamed two controversial VAR decisions for leaving West Ham staring down the barrel of relegation from the Premier League.
After Murillo's own goal gave the Hammers a lead, they thought they had doubled their advantage when Crysencio Summerville lashed the ball home from the edge of the box.
LATEST SPORT NEWS
Goalkeeper Alphonse Areola came out to punch clear a corner and caught Morgan Gibbs-White in the face with VAR sending referee Tony Harrington to the monitor
|PA
However, a VAR check spotted new signing Taty Castellanos in an offside position, some time earlier, in the build-up.
It was a pivotal moment, as seconds later Forest equalised when Nicolas Dominguez met Elliot Anderson’s corner at the near post and his header looped up and over Kyle Walker-Peters at the far post.
Nuno said: “That was the crucial moment of the game, a two-goal lead. We were playing good, creating problems for Forest.
"All the stadium felt the pain of the goal ruled out. Forest scored but we had chances to change it around."
For West Ham, the defeat compounds their relegation fears, leaving them stranded seven points from safety
|PA
Worse was to come when, with two minutes remaining, goalkeeper Areola came out to punch clear a corner and caught Morgan Gibbs-White in the face.
No Forest players appealed, yet the VAR sent referee Tony Harrington to the monitor and after he relayed the bad news to the home crowd, Gibbs-White lashed in the winner.
Nuno added: "I was a goalkeeper and you cannot stop your movement, you go for the ball - it has a trajectory and a line. How many times you see this happen and nothing given. Not in my days and not today, it should not be given.
"That is how I see it. We have the referee, the VAR and we have to accept. For me it is not a penalty."
West Ham came off second best to a team just as bad as them
|PA
Soucek, who headed the ball clear before Areola caught Gibbs-White, fumed on Sky Sports: "It’s a joke, I just saw it.
"I came to the Premier League because it was the best league in the world and it’s more like basketball. Areola went for the ball and we didn’t know why VAR were looking at it."
Yet ultimately, West Ham came off second best to a team just as bad as them, and where the gap to safety would have been just one point with a victory over Sean Dyche’s side, it is now seven.
“It is a big gap but it is not over,” said Nuno, unconvincingly. “We have to keep believing, working hard and chasing this good run that we need.”