With Premier League leader Liverpool having extended the gap at the top with a win over Wolves, City was fortunate not to fall behind in the first half when Lys Mousset had a goal harshly disallowed by VAR.

However, there was more controversy to follow, with the visitor incensed after referee Chris Kavanagh failed to stop the play despite accidentally blocking off John Fleck in the build-up to Sergio Aguero's opener.

VAR did come to the Blades' assistance when it deemed John Egan had not deliberately handled a Riyad Mahrez shot, though City had the points wrapped up when De Bruyne lashed in with eight minutes remaining.

With Mousset having squandered an early header, United thought they had the lead when the striker kept his cool to slot beyond Claudio Bravo, who was starting in place of the suspended Ederson, only for VAR to disallow the goal for a marginal offside call.

Mousset got the better of City's defence again prior to half-time, yet sliced his effort into the side-netting after latching onto Oliver Norwood's pass.

Despite its poor display, City took the lead six minutes into the second half - Aguero clinically drilling in his 10th league goal of the season.

United was adamant the goal should not have stood due to the referee's accidental interference, but VAR once more went against them.

City then wanted a penalty when Egan blocked Mahrez's shot, though their claims were rejected despite the ball hitting the defender's arm.

Any hopes of a comeback were ended soon after as De Bruyne calmly swept home, though Billy Sharp went agonisingly close to setting up a grandstand finish with a looping header which hit the upright and rolled across the line as United's unbeaten run on the road came to an end at nine.