It was the Red Devils' first Premier League hat-trick since Robin Van Persie hit three in 2013, extending their unbeaten run to 13 matches and boosting their top-four hopes on a night that had initially been pencilled in for a neutral venue.

Chris Wilder called this a clash between his Ford Fiesta and a Ferrari, so the Blades boss could have done without his defence stalling with seven minutes on the clock as Martial turned home Marcus Rashford's cross.

Paul Pogba put in a promising performance on his first start since September and there was a snapshot of what could lie ahead alongside Bruno Fernandes, with the pair involved before Martial met Aaron Wan-Bissaka's cross.

The France international moved onto 19 goals for the season – the best return of his career – by superbly scooping the ball over Simon Moore late on as the hosts secured a surprisingly routine win.

Before United's first-ever competitive behind-closed-doors match at Old Trafford, the club paid their respects to the late, great Tony Dunne with a moment of silence and a new banner remembering 'The Quiet Man'.

Both sets of players took a knee as part of the Black Lives Matter movement before play got under way in 30 degree heat, with the hosts making a scorching start to proceedings.

The Blades' rejigged backline failed to deal with a throw-in from the right and Rashford drilled in for Martial to tuck in at the near post with just seven minutes on the clock.

It should have been two shortly afterwards. Having blocked a George Baldock shot, Solskjaer's side broke at speed and Rashford put Martial through.

The Frenchman turned the ball back to his team-mate after drawing the goalkeeper, but Rashford somehow scuffed his attempt wide under pressure.

Fernandes saw a free-kick tipped over and Rashford miscued another shot shortly afterwards as he failed to give a wonderful team move – and inspired Pogba pass – the finish it deserved.

Harry Maguire saw a goal ruled out against his former club after holding Phil Jagielka down when meeting a corner with a thumping header, with Solskjaer's side losing some momentum after the much-needed drinks break.

But as the hosts' frustrations became increasingly audible, Martial managed to diffuse growing tension.

Fernandes and Pogba coolly moved the ball onto Wan-Bissaka, who impressively turned Enda Stevens and crossed for the forward to sweep home at the near post.

That goal took the edge off the second half, as did the heat and natural rust that followed such a long period out.

But the Reds remained in control, with Mason Greenwood seeing an effort deflect wide and Pogba showing wonderful close control before Martial hit high into the East Stand.

Greenwood fizzed off target before Martial wrapped up his hat-trick in the 74th minute, showing wonderful composure to scoop the ball over Moore after playing a one-two with Rashford.

Solskjaer took off the hat-trick hero as the Manchester United boss made five substitutions in one fell swoop with the encounter over as a contest.