Richard Stearman was the hero as United overcame Middlesbrough at Bramall Lane on Wednesday evening.
The substitute produced a powerful header in front of the Kop just after the hour as the Blades kept the pressure on those above in the Sky Bet Championship. The visitors finished the game with ten-men with Daniel Ayala seeing red for two bookable offences.
For the clash against Boro, boss Wilder was forced into changes. Basham missed out through suspension, whilst O'Connell was absent with a tight hamstring. Cranie, Duffy and McGoldrick all started, with Madine dropping to the bench where he was joined by Hogan, Coutts and Bryan.
United started brightly, with Duffy engineering space for a shot that forced Randolph in a top save, before Friend did just about enough to deny Baldock on the rebound, at the expense of a corner, which came to nothing. Boro's first shot, saw Saville drag an effort wide in the 17th minute.
Flint was forced off with a hamstring problem for the visitors, before Shotton was booked for a lunge on Dowell. United looked to seize the advantage moments later, but Randolph cut out McGoldrick's low cross, with Sharp jogging on the spot.
As the first-half ended it's later stages, Hugill had a couple of sights of goal, firstly the danger was snuffed out by a timely block, before Henderson showed agility to tip an effort of the bar. Before the break, Baldock limped off and was replaced by Stearman, Cranie moving forward to the vacated wing-back position. The last action, saw Sharp have a shot saved by Randolph.
At the break, Madine replaced Duffy. Stevens and then Henderson were needed at one end to deny Friend and Downing, before United had strong appeals for a penalty waved away by referee Woolmer, despite Shotton appearing to pull back Madine, who still managed to get an effort on target which was saved.
Tempers were threatening to boil over as United appealed for a couple of fouls by Ayala on Madine, but the defender was then booked for a cynical foul on McGoldrick, from which Norwood fired high and wide. Moments later the Blades did find the back of the Boro net, but Sharp's effort from Madine's shot was chalked off for offside.
But United weren't to be denied and took the lead in the 61st minute. Norwood's inch perfect cross was headed home to the delight of three sides of Bramall Lane by substitute STEARMAN and three minutes later, United seized a numerical advantage as Ayala was sent off for another mistimed challenge, this time on Dowell.
With 16 minutes remaining, Boro almost snatched an equaliser, but Henderson denied the advancing Assombalonga. Moments later Fleck was cautioned following a challenge on Obi Mikel, despite referee Woolmer already awarding United a free-kick.
Sharp received a standing ovation as Coutts replaced the skipper with three minutes remaining and United saw the game out to register a deserved fifth consecutive home victory in the league.
Blades: Henderson, Baldock (Stearman 44), Stevens, Fleck, Dowell, Sharp (Coutts 87), Egan, Norwood, McGoldrick, Duffy (Madine 45), Cranie.
Unused: Lundstram, Hogan, Stearman, Bryan, Moore.
Boro: Randolph, Obi Mikel, Friend, Ayala, Shotton, Hugill, Howson (Van La Parra 81), Fry, Saville (Assombalonga 66), Flint (Downing 33), Wing.
Unused: Konstantopoulos, Clayton, Fletcher, Besic.