Just nine of the 32 third round ties had VAR in operation. This was one of those that did and it appeared to make little difference.
This low-key affair was all but settled by a goal controversially awarded to West Ham despite VAR Peter Bankes and his team having the opportunity to review the incident over and over again.
Amid a first-half scramble in the Leeds box, Jarrod Bowen’s intervention from an offside position was overlooked and Manuel Lanzini’s goal was given.
Manuel Lanzini stuck his tongue out in celebration after he broke the deadlock for West Ham
The Argentine was able to find a pocket of space and fire beyond the retreating Leeds defence
Luke Ayling on the line could do nothing to keep out Lanzini’s finish – but it was sent to the VAR
Jarrod Bowen (centre) was offside in the move but the VAR adjudged he had not interfered
There was no debate about Bowen’s clinical finish with the last kick of the game but the defining moment was the questionable first-half call.
What was not in doubt was that, ultimately, West Ham deserved the place in round four having done most of the running at the London Stadium.
But Leeds had good grounds to feel aggrieved at the goal that set them on the way to a fifth successive third round exit as their remarkable FA Cup hoodoo continued.
Decimated – missing 10 players – and youthful as a result, with Marcelo Bielsa forced to hand full debuts to Lewis Bate, Leo Hjelde and a first start to Sam Greenwood – all three teenagers – the goal that gave them an uphill task would have been a hard one to accept.
Leeds arrived in east London decimated by injuries as Sam Greenwood took aim from distance
Marcelo Bielsa (right) barked instructions at his players as Leeds looked to gain a foothold
MATCH FACTS AND PLAYER RATINGS
West Ham (4-2-3-1): Areola 7; Fredericks 7, Diop 6.5, Dawson 6.5, Johnson 6.5; Rice 8, Soucek 6; Bowen 8, Lanzini 7 (Fornals 76, 6), Vlasic 7 (Masuaku 88); Antonio 7.5 (Yarmolenko 95).
Subs not used: Randolph, Fornals, Noble, Masuaku, Král, Oko-Flex, Alese, Baptiste
Scorer: Lanzini 34, Bowen 93
Manager: David Moyes 7
Leeds (4-2-3-1): Meslier 7.5; Ayling 6.5 (Forshaw 60, 6), Llorente 6, Hjelde 6.5 (Summerville 78), Firpo 7 (Drameh 68, 6); Koch 6, Bate 6; James 6, Klich 6, Harrison 6; Greenwood 5 (Raphinha 46, 6).
Subs not used: Klaesson, Dallas, McCarron, Jenkins, Moore
Manager: Marcelo Bielsa 5
Referee: Stuart Attwell 5
This fixture, which will take place again in the Premier League on Sunday, was picked for TV to some consternation.
The first half hour was not much of an advert for the competition or justification of that decision.
Then came some messy defending from Leeds and, finally, a major talking point.
Nikola Vlasic gathered in Michail Antonio’s cross and wriggled away Hjelde who stuck to his task well to hold up the Croatian with a last-ditch tackle.
Illan Meslier tried to grab the loose ball but missed, Junior Firpo attempted to kick it clear though only succeeding in presenting it to Lanzini who gleefully swept the opener into the net.
While Lanzini ran off to one of the corners celebrating with that familiar, West Ham, arms crossed gesture, Leeds protested and, it appeared, with good reason.
Meslier’s effort to tidy up the situation was hampered by a seemingly offside Bowen.
As the VAR check continued, Leeds seemed so certain the goal would be chalked off Ayling returned the ball from halfway to his goalkeeper to restart the game with a free-kick.
But, to some surprise, Stuart Attwell pointed to the spot and West Ham led despite Bowen’s interference. By half-time their advantage should have been greater.
Antonio fired one effort wide on the stretch and Ryan Fredericks was unable to apply the finishing touch to a flowing move involving Bowen, who had earlier had an effort cleared off the line by Ayling.
Leeds, in contrast, had barely posed an attacking threat so the half-time introduction of Raphinha for Greenwood was little surprise.
Ayling found himself busy in the early exchanges as he was on hand to block a strike on the line
He could do nothing about Lanzini’s goal and their subsequent VAR appeals were waved away
Still it was West Ham who continued to look the most dangerous. Antonio flashed a ball across the box that was begging to be converted before Bowen broke into space but saw his shot blocked by Meslier’s legs.
A rare chance arrived for Leeds as the game entered the final 20 minutes.
Mateusz Klich smashed a volley goalwards and Leeds had two players well positioned. But Daniel James only got half a touch and that distracted Jack Harrison who could not readjust his feet to turn the ball in.
And after Fredericks went close again, James diverted another Leeds opportunity wide when he should have scored, blowing the chance to take the game to extra time.
The importance of that miss was underlined at the death when Bowen slipped Antonio’s pass through Meslier’s legs.
Fans were made to wait as the VAR watched the move over and over before awarding the goal
There was a level of animosity between the home (right) and away (left) fans after the first goal