The Blades defenders totally stopped playing, believing the Newcastle midfielder to be offside, while goalkeeper Dean Henderson made no attempt to save the ball as Shelvey fired into the back of the net, knowing the goal would be checked.

It was a very tight decision but Carroll was inches onside and the goal stood to give the Magpies a vital victory on Thursday night.

The hosts' first defeat since losing at home to Liverpool on September 28 still leaves them in the top half of the table, while Newcastle are now level on points with Chris Wilder's side.

Sheffield United started the game well. Enda Stevens' shot deflected off the foot of Javier Manquillo and had to be tipped over the crossbar by Martin Dubravka.

Another corner caused panic in the Newcastle six-yard box as Oli McBurnie lurked for a tap-in but the visitors managed to clear the danger.

Good link-up play between Billy Sharp and McBurnie allowed the latter to surge towards the penalty area, with the Blades' club-record signing curling his effort narrowly wide of the top corner.

However, it was Newcastle who opened the scoring with their first real threatening attack after 15 minutes.

It was a good cross from the right by Manquillo to the far post where Saint-Maximin had got a run on Chris Basham and beat the home defender in the air to head the ball down into the bottom corner from eight yards out.

It needed a fine save from Dubravka five minutes later to preserve his side's lead as he flung himself to his left to push away a McBurnie header.

The Blades threatened again either side of the half-hour mark as Sharp, stretching to get on the end of Stevens' through ball, could only poke his attempt into the side-netting, before John Egan sent a powerful header straight at Dubravka.

The Slovakian goalkeeper ensured Newcastle would go into the break ahead when he punched clear a fiercely-struck free-kick by Oliver Norwood in first-half injury time.

Dubravka was busy again early in the second half as he showed good agility to help another McBurnie header over the crossbar.

Wilder's side were dominant as they pinned Newcastle inside their own half, although the Magpies were organised and disciplined in their defending.

Lys Mousset, with four goals in his last six games, was brought on after 63 minutes to help turn the tide for the hosts.

However, the game swung in Newcastle's favour in the 70th minute with the VAR decision and the Blades never regained their momentum.

David McGoldrick and Luke Freeman were introduced from the bench in an attempt to get back into the match but the Magpies soaked up the late pressure for a third win in five Premier League outings.