The Blades recorded the largest winning margin of the season to overwhelm Scunthorpe United at Bramall Lane on Tuesday evening.
Nigel Clough's side made full use of the game in hand to record three more vital points.
Jose Baxter scored two penalties whilst Jason Holt scored his first Blades goal and Jamie Murphy added to his tally in the second half.
Injuries to goalkeeper Howard and Done meant chief Clough was forced into two changes for the Sky Bet League One encounter, although the latter was amongst the substitutes. Turner and Flynn came into the starting line-up and Brayford took over the captain's armband.
In a subdued start, Scunthorpe were quick to cut off United's supply lines out of defence, promoting the long-ball, whilst the first action for the referee was to book Freeman for a foul on McSheffrey.
Coutts, Murphy and Harris came close to working a good move down the left before United opened the scoring with the first attacking set-piece, a corner conceded by Lundstram on 14 minutes. Coutts and HOLT worked a short routine with the latter's low shot-cross to the back post evading everyone and finding the bottom corner.
Baxter was off target with a long-range effort and a Harris free-kick from right on the edge of the box following Townsend's foul on Flynn was blocked as the home side remained on top. Scunthorpe had to wait until the half hour before their first chance and then Llera's 30-yard free-kick was deflected over by the Blades wall.
A clash with Llera saw Davies warned by the referee and the two were involved again in the build up to the second Blades goal but play continued and resulted in Flynn stepping across and getting fouled by Canavan - penalty was the decision. After scoring from the spot on Saturday, BAXTER stepped up and hammered home.
Before the break there was a spell of defending to do to protect the two-goal lead, Harris cutting out a McSheffrey cross, which was destined for Adelakun.
The home side kicked off the second half with an impressive move, beginning with Basham winning possession from Madden 90 yards from the Scunthorpe goal and Baxter, Coutts and Davies were all involved before Murphy won a corner from Canavan.
For Scunthorpe, shots from Adelakun and McSheffrey were off target, whilst on 62 minutes, Flynn got around the back of the visiting defence but Clarke cleared from under his own crossbar.
The pace slowed, although the Blades continued to boss possession. An unnecessary foul by Basham presented Scunthorpe with a free-kick but van Veen curled wide from 20 yards.
In the final 15 minutes, the hard working displays from both Davies and Coutts received ovations when they were replaced by McNulty and Doyle respectively, as did Flynn moments later when Ben Davies took his place, which was seconds after the Blades added a third goal. Freeman's clip through the visiting defence put MURPHY and the clear and he calmly lifted over the helpless Daniels.
Former Wednesday defender Llera was booked on 83 minutes and sent off a minute later, guilty of hauling down McNulty in the penalty area from a Ben Davies corner for a second booking. BAXTER again stepped up and converted the spot-kick, this time in front of the Kop.
The closing minutes, plus three added, were largely incidental as United kept possession to keep a second consecutive clean sheet.
Blades: Turner, Harris, Brayford, Basham, Flynn (B. Davies 82), Murphy, Baxter, Coutts (Doyle 79), Freeman, S. Davies (McNulty 75), Holt.
Unused: Alcock, Willis, Done, Adams.
Scunthorpe: Daniels, Canavan, Madden, Adelakun (Wootton 60), Townsend, Lundstram, O'Neil, McSheffrey (Boyce 86), Llera, Clarke, Osbourne (van Veen 60).
Unused: Evans, Williams, Davey, Anyon.