The Blades were forced to come from a goal behind in what was a frantic seven minute spell in the second half which saw the Brewers first take the lead through Justin Richards before David McAllister and Erik Tonne's successful strikes handed the visitors the lead and the victory in their first professional outing at the Pirelli Stadium.
Danny Wilson had made five changes from the side which faced Yeovil and settled for a 3-4-3 formation; Long, Mendez-Laing, Slew, McAllister and Philliskirk all started, whilst Simonsen, Jean-Francois, Quinn, Montgomery and Cresswell made way.
Albion saw the first bit of action come their way, McGrath fired over following the game's first corner whilst at the other end Collins headed over Flynn's delivery in what were equal opening exchanges. Maghoma, the hosts right winger saw plentiful of the ball early doors and a foul on him by Mendez-Laing which almost set about an early opener for the L2 side. McGrath's free-kick flew under the wall but Long was equal to it.
The winger again caused problems for the Blades and after rounding Lowton his effort cannoned off the crossbar and following a challenge on Maguire - Richards was the first to go into the referee's notebook. Maghoma again saw his opportunity spurned, this time dragging wide as the hosts threatened once more. United sprung an attack which saw Philliskirk in the back of the net after his header from Mendez-Laing's cross bounced agonisingly over the crossbar.
Before the break there was still time for two more Burton attacks, Austin headed over Maghoma's free-kick and Phillips drive was saved by Long as the half ended goalless. Ellian Parrino was introduced at half-time for the Blades with Philliskirk making way with Wilson switching to a 4-4-2 formation.
Referee Gibbs added McGrath into the bookings lists after a foul on Slew and following the change in formation United pegged back the hosts and was to be denied when Mendez-Laing and Doyle both saw shots blocked. Long required treatment after punching away a cross from the left wing which saw him with a bloodied nose
On 73 minutes his next job was to pick the ball out of the net, RICHARDS controlled after being put through by Yussuf and curled the ball into the top corner; 1-0. In reply Tonne was introduced for Mendez-Laing and this proved to be an inspiring substitution but only after McALLISTER brought the ball down on his crest before firing into the bottom corner of the goal.
McAllister almost made it two when his effort deflected up onto the crossbar with the hosts struggling to contain their opponents. With ten minutes left on the clock Jordan Slew's pass found Norwegian TONNE who from 25 yards hit a shot hard and low and too hot to handle for Atkins as the ball cannoned into the bottom corner.
As the game came to a knife edge United advanced further and almost took the game beyond Burton - McAllister flashed wide from distance and Slew fired across goal.
Burton Albion: Atkins, McGrath, Moore, Corbett, Richards, Zola (Yussuf 67), Austin, Phillips, Maghoma, Blanchett, Dyer.
Unused: Poole, Webster, James, Palmer.
Sheffield United: Long, Lowton, Mendez-Laing (Tonne 74), Doyle, Flynn, Slew, Collins, Maguire, McAllister, Porter (Harriott 88), Philliskirk (Parrino 45).
Unused: Simonsen, Conneely.