Billy Sharp's second-half penalty sent Sheffield United into the FA Cup quarter-finals with a 1-0 victory against Bristol City.

The Blades club captain tucked away the spot kick after VAR ruled that Alfie Mawson had deflected a goalbound effort from David McGoldrick on to the crossbar with an arm, an offence for which he was shown a red card.

Before that 65th-minute incident, the Sky Bet Championship team had succeeded in frustrating the side bottom of the Premier League, as Chris Wilder's men dominated possession without creating too many clear-cut chances. The story of their season.

City can also take much credit for the way they reacted after the setback, but it was the Blades who advanced to the last eight for the second year running.

And Wilder will hope his players can continue to use their victories in the FA Cup to breed life into their Premier League survival hopes.

The hosts began positively but it was City who had the first chance of the game when the ball dropped to Tomas Kalas on the left side of the box following a free-kick. His shot forced Aaron Ramsdale to get down to his left and get a strong hand on the ball to push it away.

That would be as dangerous as the Championship club looked as the Blades dominated possession in the first half, without really troubling Max O'Leary in the away goal too much.

However, there was a let-off for City after nine minutes. Jayden Bogle cut in off the right flank and exchanged passes with David McGoldrick before finding Max Lowe's run into the box. Lowe only had the goalkeeper to beat but smacked his effort off the top of the crossbar and behind into the stands.

Bogle should have done much better than head the ball straight at O'Leary when he was found by Ethan Ampadu's pin-point cross 10 yards out just before the half hour mark.

Despite their dominance, chances were few and far between for the hosts and it was a sign of their frustration that John Lundstram decided to shoot from 30 yards out as half time approached. Bogle then curled an effort well off target from the edge of the box.

City had a huge chance right at the start of the second half. Joe Williams put Nahki Wells clear on the left but he opted to shoot straight at Ramsdale when he had the unmarked Jamie Paterson screaming for a tap-in in the middle. It was definitely the wrong decision.

City's goal led a charmed life just after the hour mark. Mawson deflected David McGoldrick's goalbound effort on to the crossbar before Kalas blocked the follow up on the goal line.

However, VAR showed that Mawson had turned the ball on to the woodwork with his arm, leaving referee Rob Jones no choice but to send him off for denying a goal scoring opportunity.

Sharp tucked away the penalty into the bottom corner, although O'Leary dived the right way and was close to it.

McGoldrick came close to quickly making it 2-0 but curled his shot just wide of the far post.

It could have got worse for City when VAR checked whether O'Leary had handled the ball outside of his area, but the decision was it hit his chest.

Wilder's side did enough to win the tie, thereafter. Substitute Oliver Burke saw an effort cleared from in front of the line in injury time after he had beaten O'Leary to the ball out wide on the left.