Billy Sharp again proved Sheffield United's matchwinner from the spot as the Blades beat 10-man Bristol City 1-0 to take them through to the FA Cup quarter-finals.
Sharp beat Max O'Leary from 12 yards with an excellent penalty into the bottom corner after 66 minutes, to give the Blades the narrow victory they deserved against a dogged but limited Bristol City side.
The Championship visitors' task was made harder with Alfie Mawson sent off for a handball on the line leading to that penalty, which was only spotted after a review by VAR official Martin Atkinson.
United had the better chances in both halves, with Max Lowe striking the bar before the break and David McGoldrick pulling a fine stop out of O'Leary after it, while Nahki Wells selfishly wasted the Robins' best chance of note with Jamie Paterson waiting for a tap-in. But Sharp's typically fine finish ensured there was no upset as the Blades reached the sixth round.
Sheffield United: Ramsdale (7), Basham (6), Egan (7), Ampadu (7), Bogle (7), Lundstram (7), Fleck (6), Lowe (7), McGoldrick (6), Brewster (5), Sharp (7).
Subs: Norwood (6), Burke (n/a).
Bristol City: O'Leary (7), Hunt (6), Kalas (6), Mawson (6), Moore (6), Towler (6), Vyner (5), Williams (7), Paterson (7), Wells (5), Diedhiou (6).
Subs: Nagy (5), Massengo (6), Palmer (7), Semenyo (6).
Man of the match: Billy Sharp.
Robins' wings cut by hard-working Blades
Sheffield United controlled the play from the off but found Bristol City difficult to break down in the opening stages. Instead, it soon became clear set-pieces would be the Robins' plan of action, and from a Paterson free-kick Tomas Kalas' half-volley was well saved by Aaron Ramsdale.
Moments later the hosts almost found their breakthrough, as Lowe received a lovely pass from opposite wing-back Jayden Bogle before striking the bar when he should have scored.
Moments before the interval Taylor Moore flicked another Paterson delivery over the bar when well-placed, and moments after it Wells wasted the Robins' best chance of the match by firing at Ramsdale from a tight angle when squaring to Paterson would have left his team-mate a simple finish.
Just after the hour, the game's defining moment swung the tie in the Blades' favour. What initially appeared a superb goal-line Mawson clearance from McGoldrick's effort was, after a VAR review, found to be a handball - and a penalty, and red card, were awarded, with Sharp making no mistake.
From then the Robins were up against it, and offered little hope of a comeback against their Premier League hosts. Instead, McGoldrick twice went close as Sheffield United saw out victory easily to reach the last eight and record another welcome win in an increasingly resurgent 2021.
Man of the match - Billy Sharp
As well as making the chance for McGoldrick which led to the penalty, and red card, Sharp stepped up to score again from the spot with another match-winning performance for Sheffield United.
What the managers said
Sheffield United boss Chris Wilder: "I thought we played well and were in control against stubborn opposition. We've
had some tight games against Bristol City in the Championship and they have turned us over a couple of times.
"But I felt we were always comfortable and comfortable in possession and we deserved to get through to the quarter finals. Getting through to the last eight for two years on the spin is good for us and now we have to use that momentum
going into an incredibly competitive next few games.
"The FA Cup has put belief and confidence into the boys and we will hopefully use another win tonight to go and get some more results in what is a very challenging period for us."
Bristol City boss Dean Holden: "I thought it was a really disappointing way to lose a game of football and it is difficult to take. I think if the game was played at Ashton Gate it's not given, as there's no VAR at Championship stadiums.
"Alfie feels responsible, but he shouldn't to be honest as it's a heroic bit of defending. I'm really disappointed because I thought our performance levels were good. I think we acquitted ourselves really well and we've been on the wrong end of a decision. "It's difficult but we will pick ourselves up and go again."
- Sheffield United have reached the FA Cup quarter-final in consecutive seasons for the first time since doing so in 2002-03 and 2003-04.
- Bristol City haven't won an FA Cup away game against a top-flight side since January 1994 (1-0 v Liverpool), with tonight being their eighth attempt at doing so since then (D3 L5).
- After failing to win any of their first eight home games in 2020-21, Sheffield United have now won four of their last six games at Bramall Lane in all competitions (L2).
- Billy Sharp has been directly involved in half of Sheffield United's goals at Bramall Lane in all competitions this season (6/12), scoring five goals and providing one assist.
- Sheffield United striker Billy Sharp has converted nine of his last 10 penalties in all competitions (excluding shootouts), including all three spot kicks he has taken this season.
- Alfie Mawson is the first Bristol City player to be sent off in an FA Cup game since January 2012, when Stephen Pearson was dismissed in a third round match against Crawley Town.
Sheffield United have a five-day rest before their next game, a trip to the capital to face West Ham on Monday; kick-off at 6pm.
Bristol City are back in action at Watford on Saturday afternoon; Kick-off at 3pm.
FA Cup 2020/21 - key dates and draw
The FA Cup schedule has been confirmed, with the final set to take place at Wembley on Saturday, May 15.
There will be no replays this season to help ease fixture congestion.
The draw for the quarter-final will take place on Thursday evening, ahead of the final fifth-round tie of the week between Barnsley and Chelsea.
- Quarter-finals: Saturday, March 20
- Semi-finals: Saturday, April 17
- Final: Saturday, May 15