The victory, given to Micky Adams' side by Eric Lichaj's second-half own goal and a Bjorn Helge Riise strike, will not drag them out of the relegation places, but it does offer further proof that they have what it takes to avoid the drop.
The Blades were the better side throughout against the division's top scorers, who have now gone two games without a goal and must now be ranked as firm outsiders to make the second automatic promotion spot theirs, especially as they will be a striker light for three games with Billy Paynter seeing red late on.
With 55 minutes gone, Stephen Quinn put Nick Montgomery in on Kasper Schmeichel's goal and his cross was turned into his own goal by Lichaj.
The Villa loanee could do little else with home forwards lurking behind him, and with 16 minutes left on-loan Fulham man Riise broke on to a Quinn pass and, from inside Schmeichel's six-yard box, drilled home hard and low.
Paynter saw red with two minutes remaining following an altercation with Shane Lowry, with the Australian defender suggesting he had been stamped on.
Source: PA
Source: PA