This was Howard Wilkinson's (ex-Wednesday) first ever defeat at Bramall Lane when in charge of any team against United.
Goalkeeper Jurgen Macho and Gavin McCann was the only first team players that was involved in the 3-0 defeat at Chelsea on Saturday.
Neil Warnock had got Wilkinson wrong as Warnock expected Wilkinson to field a full strength squad in the hope that the Black Cats would win the competition and thus gain automatic entry into UEFA Cup.
Wilkinson obviously did not feel the same way, although the team that amazingly beat Arsenal 3-2 (after being 2-0 down) was the same as that against United.
United seem to have every chance of reaching the final as the top FA Premier League clubs keep spilling out (lets just hope that Rotherham United beat holders Blackburn Rovers at Ewood Park).
However, Neil Warnock has made it clear that he feels a Nationwide League club can make it all the way and to win it. He also feels that United have a very good chance of winning it after beating off Leeds in round 4 and now Sunderland.
After only 11 minutes United almost took the lead when a Michael Tonge free-kick whipped around the Sunderland defenders, Macho came out to collect but Murphy came rushing in only to stab the ball wide.
After that near-miss chance Macho was outstanding (my man of the match for opposition), he denied a superb Carl Asaba header, Michael Tonge 18 yard shot as well as a Michael Brown effort.
Sunderland too were guilty of wasting chances, especially after Kevin Kyle's 22 yard thunder bolt was saved by Kenny's legs, Michael Procter then fired wide from the resulting save.
The Mackens always look Sharpe upfront, danger man David Bellion sprinted on left wing where his cross was volleyed by ex-Ipswich striker Marcus Stewart but Robert Page blocked it well.
Moments later Kevin Kyle was through one-on-one with Paddy Kenny but instead of shooting he decided to try and pass to the awaiting Stewart but again he was denied by the inform Page.
Half-Time: Sheffield United 0-0 Sunderland
With both teams being denied goals by two superb goalkeepers, United had to try and finish off any chances that came there way.
Eight minutes had gone in second half when Sheffield United finally took the lead.
Phil Jagielka tore down right wing where his cross took a slight deflection which beat Mancho, Stanislav Vaga attempted to hook the ball away but it hit the crossbar, but there was Australian International Defender Shaun Murphy to stab home from two yards out.
Two minutes later United booked there place in Quarter-Finals (along with Crystal Palace and Manchester United) when Stuart McCall cleverly found Peter Ndlovu on edge of 19 yard box, using skill and speed he whipped in a world class cross onto far post.
The cross found Wayne Allison unchallenged and had the simple task of heading home, which he did with style.
Sunderland were absolutely stunned but despite that they had chances to get back into the game, Kenny pulled off another fantastic save when Darren Williams shot from close range.
Referee Alan Wiley gave a free-kick when Jon Harley's block was picked up by Kenny, Wiley said it was a back pass and the free-kick was given. With all 11 men on line, Varga's shot just could not beat them and was cleared out for safety.
In the final minute substitute Paul Peschisoliso had a glorious chance to make it three when he was one-on-one with Macho but he lost his balance after rounding keeper.
Full-Time: Sheffield United 2-0 Sunderland
Man of the match: This award is really difficult to award as each player from Paddy Kenny down to Wayne Allison all player superb, it was like watching Brazil. I will give the award to one special player, Peter Ndlovu, his pace and skill tore through opposition and his brilliant cross helped to win the game.