United avenged a defeat by Norwich earlier in the season with a deserved victory at Carrow Road.
James Wilson, on his full debut, opened the scoring and substitute Clayton Donaldson added a second after the break.
Leonard, Evans and Wilson made their full debuts with Lundstram, Duffy and Donaldson all dropping to the bench, where they were joined by new boy Holmes and young goalkeeper Eastwood after Blackman suffered a training ground injury.
Norwich looked to make a fast start in front of their own fans but United opened the scoring from the first corner, which Basham and Baldock combined to force. Fleck delivered, the home side half-cleared but Basham and O'Connell were a nuisance before WILSON spun and beat goalkeeper Gunn.
It was not the start the Canaries wanted and they looked for an immediate response. Evans was well placed to cover when Murphy turned Basham and then Moore collected a free-kick from Maddison.
Before the 20-minute mark, Gunn was forced into a double save from Leonard and then the goalkeeper prevented Wilson grabbing a second after Clarke flicked on Fleck's cross. Also, Baldock fired over as United looked to get on top.
As half-time approached, Norwich had a spell of pressure. Murphy ran onto Oliveira's pass but Moore was well placed, the goalkeeper then pushed away Maddison's free-kick. The final chance of the half also dropped to the home side but Klose's drilled effort was wide.
United started brightly in the second half, Steven hit the outside of a post and Gunn saved from Leonard after Norwich were caught trying to play out from the back. Leonard had another effort blocked after Fleck tried to put through substitute Donaldson, who did not take long to make an impact.
Following Stearman's clearance, Tettey made a mess of a back pass and Gunn backed off, allowing DONALDSON to progress into the box and clip over the goalkeeper.
United's two-goal advantage, however, lasted a matter of moments as a corner from the right saw PINTO loop a header over Moore into the far corner.
Gunn saved Clarke's half-volley but the Canaries goal gave them momentum and for the final 15 minutes they were on the offensive. Moore pushed over Zimmermann's header and Maddison was in the clear but failed to control Hoolahan's chipped pass.
Baldock blocked from Murphy and Stevens robbed Hoolahan in the same move as United defended stoutly. Oliveira turned and fired over when in a good position, whilst five minutes of added time gave the home side hope.
But all they could muster were a couple of hopeful free-kicks into the box, including one when goalkeeper Gunn added himself to the attack, but again the Blades defended well to secure a valuable away win.
Norwich: Gunn, Pinto, Reed (Vrancic 59), Zimmermann, Oliveira, Murphy, Klose, Maddison, Lewis, Tettey (Stiepermann 87), Hanley (Hoolahan 59).
Unused: Husband, Raggett, McGovern, Cantwell.
Blades: Moore, Baldock, Stevens, Fleck, O'Connell, Basham, Clarke, Wilson (Donaldson 58), Leonard, Stearman, L Evans (Lundstram 81).
Unused: Sharp, Duffy, Lafferty, Holmes, Eastwood.