The Blades chalked up a first ever win at Glanford Park and two ex Scunthorpe United men were instrumental.
Nigel Adkins was the Scunthorpe manager for four years and Billy Sharp - today's goalscorer - was one of his players. This was United's third consecutive clean sheet and third consecutive 1-0 success.
Manager Adkins made just one change from the victory over Coventry City with Iron old boy Sharp starting - Sammon dropped to the bench and was joined by the fit-again Campbell-Ryce.
In a lively start, the Blades quickly applied the pressure and forced a chance after only five minutes; Woolford's inswinging free-kick finding Hammond at the back post but the loanee could only side-foot over before colliding with a post.
The visitors also won a number of early corners, including a pre-planned routine that saw Woolford's shot blocked, whilst Brayford's drilled 25-yard effort was well held by goalkeeper Daniels.
Scunthorpe's first opportunity, on 17 minutes, saw Bishop and then Wiseman work hard to put the ball into box but Long saved from Rowe and the follow up was deflected wide for a goal-kick. The second home chance came from a Basham handball but Bishop's free-kick was saved at the near post by Long.
Scunthorpe had a spell on the offensive but the Blades hit back. On the break, Basham and Sharp were involved before Coutts stung the palms of Daniels, who looked on nervously moments later when a Sharp volley on the turn flew just over.
Late in the half the Blades fans applauded McEveley has he halted Wootton as Scunthorpe broke and as the referee's whistle signalled half-time the visitors were on the attack again.
At the start of the second half, the Blades created three good opportunities inside three minutes but were unable to break the deadlock. It started with a good move involving crisp passes from Hammond, Coutts and Brayford before Daniels saved from Wooldford and then Sharp cut in from the left and also saw his shot saved. Then followed a run from Coutts, setting up a cross from Done, but Goode kicked clear with the goalkeeper beaten.
The pressure was mounting though, and the opening goal was moments away. It came from a corner and McEveley's delivery was turned in at the far post by SHARP, who then headed off to celebrate with the Unitedites at that end of the ground.
To their credit, Scunthorpe hit straight back with a spell of pressure. On the break, Madden shot at Long and Rowe would have wondered how he did not turn in a deep cross from Williams on 59 minutes. Soon after Williams chanced his arm from 25 yards but Long made an acrobatic save, turning the ball over the crossbar.
The Blades made a couple of changes but Scunthorpe remained on the front foot. Adelakun shot wide and the Scunthorpe fans were becoming increasingly frustrated as the clock ticked down, particularly after Laird overhit a couple of crosses.
Five minutes of added time saw Scunthorpe piling on the pressure with numerous long balls into the box but the best two chances came in the fifth and final minute. A Williams free-kick, from 20 yards, was deflected wide and from the resulting corner Goode inexplicably headed wide at the far post - leaving Scunny fans with their heads in their hands and the Blades fans to celebrate an early Christmas gift.
Scunthorpe: Daniels, Wiseman, Laird, Canavan, Williams, Madden, Bishop (Ness 82), King (Henderson 76), Rowe, Goode, Wootton (Adelakun 60).
Unused: van Veen, Anyon, Dawson, Clarke.
Blades: Long, Brayford, Basham (Reed 72), Coutts, Sharp, Done (Sammon 64), Collins, Woolford, McEveley (K Wallace 83), Edgar, Hammond.
Unused: Howard, Flynn, Scougall, Campbell-Ryce.