United produced the response boss Chris Wilder was asking for with an impressive away win at Reading on a cold night.
Skipper Billy Sharp scored twice, Mark Duffy found the top corner and Simon Moore saved a penalty.
The starting XI showed one change with Duffy taking the place of Leonard, who dropped to the bench. Following a back problem, Holmes was deemed fit enough to be amongst the substitutes. It was cold in Berkshire with a light dusting of snow on the pitch at kick-off.
United were bright in the approach from the first minute. Duffy had a shot blocked and Clarke fired wide after robbing a home defender on his own 18-yard box.
Clarke and Duffy were unable to take advantage of another defence error early on but a Blades goal arrived on 11 minutes. From Fleck's pass, Clarke found space down the left and his cross was turned in by SHARP at the second attempt, after Mannone had repelled the initial effort.
A couple of testing set-piece deliveries from Kelly caused problems, from one, Clement shot but Blackman saved.
United, though, were on top. Sharp was offside when he was put through by Duffy and Clarke and then Evans shot over after Reading were caught by the overload.
The momentum, however, was stifled just after the half hour when both Clarke and Blackman needed treatment at the same time following separate incidents. Both needed to be replaced, with Donaldson and Moore taking over.
United were not finished for the half though - far from it. On 44 minutes, DUFFY had options to his left and right as the Blades overloaded down the left but opted to shoot and beat goalkeeper Mannone with an unstoppable shot to the top corner, before heading off to celebrate with the bench.
With their first effort of the second half, Reading got back into the game. Bacuna's free-kick was parried by Moore but RICHARDS fired the rebound into the roof of the net.
In response, Duffy clipped a free-kick into the hands of Mannone, who also saved from Baldock after a neat pass by Sharp.
Just after the hour it appeared that Reading were handed a route back into the encounter. Stearman stood his ground as Kelly looked to advance towards goal but referee Davies belatedly pointed to the spot. Bacuna took responsibility for the penalty but Moore made a fine save, diving to his right.
And within minutes Reading were punished for the miss. Fleck's diagonal ball saw SHARP peel off his marker and beat the offside and Mannone with one swift poke at the ball.
The Reading fans and players were not happy but the two-goal cushion was restored and United looked comfortable in the remaining minutes. Donaldson and Fleck both fired wide as the Blades threatened more goals and all the home side could muster was Martin shooting wide.
Late on there were no real chances of note as the Blades completed the double over the Royals, following the 2-1 success at Bramall Lane in October.
Reading: Mannone, Gunter, Van Den Berg, Moore, McCleary (Richards 6), Bacuna (G Evans 68), Ilori (Smith 74), Clement, Bodvarsson, Martin, Kelly.
Unused: Edwards, Barrow, Blackett, Jaakola.
Blades: Blackman (Moore 34), Baldock, Stevens, Fleck, O'Connell, Basham, Clarke (Donaldson 34), Sharp, Stearman, L Evans, Duffy (Leonard 82).
Unused: Lundstram, Lafferty, Holmes, C Evans.