United's U21s claimed their first three points of 2014 with a resounding success over Birmingham City at Shirecliffe on Monday afternoon.
In front of Nigel Clough and his coaching staff, the Blades, who had shaded the first-half, hit the Blues with three second-half goals, without reply, with Julian Banton and Callum McFadzean netting, either side of a Joe Ironside penalty.
The hosts were quickly out of the block with Jahmal Smith stinging the palms of Trueman, before United's number seven shot into the sidenetting when well placed, following good hold up play by Ironside.
Sean McGinty headed wide from a McFadzean free-kick, before Trueman produced a timely intervention to tip Shaun Miller's goalbound effort over the crossbar.
Just after the half hour Miller and Birmingham's Kelly were yellow carded following a tangle on halfway, before McGee should have done better for the Blues after being freed by Hales.
At half-time Chris Morgan replaced Miller with Diego De Girolamo and six minutes into the second period United opened the scoring.
Skipper Terry Kennedy headed against the post from Louis Reed's corner, but BANTON reacted quickest to force the ball home from inside the box.
At the other end from the restart, Sutherland had a golden opportunity to equalise, having evaded the attentions of Sean McGinty, but his shot went just wide with George Long scrambling across his goal.
The game was now end-to-end, Smith headed against the underside of the crossbar from De Girolamo's centre, before United doubled the lead in the 66th minute.
A long ball forward was chased down by IRONSIDE, who was adjudged to have been upended by a combination of Bell and Kelly. United's number nine dusted himself down before sending Trueman the wrong way from twelve yards.
The Blades always looked likely to add to the tally and after De Girolamo had forced Trueman into a fine save, MCFAZDEAN volleyed home from the edge of the area to round off the scoring and cap an impressive win in the 77th minute.
Blades: Long, Paling, McGinty, McFadzean, Kennedy (Khan 71), Banton, Smith, Reed (Whiteman 67), Ironside, Miller (De Girolamo 45), Johns.