United have reclaimed our rightful place at the top of Sheffield's football hierarchy.
A 3-2 victory over Sheffield Wednesday - the result of a blistering first half performance - secured Steel City bragging rights.
Jamie Ward, Darius Henderson and a Lewis Buxton own goal gave United an unassailable 3-0 lead at the break and Wednesday's brave fight back in the second period proved to be in vain.
Loan defender Davies - a late signing on Friday - went straight into United's starting line up for the big game. He partnered Morgan in the centre of defence with Walker reverting to right-back. Harper made his home debut and Evans was restored to the forward line with Henderson, but Quinn and France dropped to the bench. Wednesday made two changes with Wood and O'Connor coming in.
The visiting fans - housed in the lower tier of the Bramall Lane stand - comprehensively failed to drowned out United's rendition of the Greasy Chip Buttie song as the electric atmosphere intensified close to 7.45pm and when referee Wiley gave the signal to kick-off the first notable action was a booking for the new boy Davies after bringing down O'Connor less than four minutes in. Potter fired the free-kick over the crossbar.
United, however, netted with the first serious move of the evening. A first corner was only half cleared, Montgomery's tenacious work resulted in a Davies header being tipped over the crossbar by Grant, but the goal followed from the resulting corner. Treacy delivered, Morgan's head down was blocked but WARD was the first to react, swiveling and shooting past Grant.
The Owls hit back with a weak Varney effort and a shot from Potter, which was on target but was well watched by Bunn, before the visitors were stung once more. Just 15 minutes had elapsed when a long Walker throw was not cleared and a shot from Evans was deflected past Grant by the outside of Henderson's left boot, widening the smiles of the majority inside the Lane.
Montgomery became the second man in the book, for a foul on Varney, and from the free-kick Wednesday fans were given a glimmer of hope. Gray delivered and Tudgay rose above Morgan and Davies but his header was tipped over by Bunn.
United lost Ward with what appeared to be a hamstring injury just after the half hour, and his place was taken by the equally pacey Cotterill.
O'Connor was booked for a foul on either Montgomery or Treacy, both were yellow card offences, and United almost made them pay from the free-kick but Henderson aimed his free header at Grant.
Wednesday's respite, however, lasted just moments as the third goal flew in - before the break. Cotterill was given the space to run down the right and his inviting cross was directed past his own goalkeeper by BUXTON's bullet header at the back post.
Before the interval Harper headed wide and even a booking for Henderson, for persistent fouls, could not dampen the spirit as a great cheer went up as the Blades players headed off for a deserved half-time drink.
Trailing 3-0 at the home of your nearest rivals, Wednesday boss Laws threw on Esajas at the start of the second half and the substitute had an immediate impact as the visitors pulled a goal back. From a right wing cross, a header by Esajas was blocked by Varney but from Walker's clearance, Tudgay fired home a left-foot volley from the edge of the penalty area. Bunn was cautioned for kicking the ball away in the aftermath.
The goal gave Wednesday impetus at the start of the second period and they attempted to apply a bit of pressure. Two Gray shots were wide and from an Esajas free-kick, which Bunn parried, Tudgay volleyed well over. Tudgay had another chance, just after the hour, but his header was blocked by Montgomery.
However, the start after the break had given Wednesday confidence and they clawed another back on 66 minutes after Cotterill's foul on Wood. From a central position 35 yards from goal, ESAJAS stepped up and drilled a low shot into the left corner of the Blades net.
At the other end, Evans fired in a shot on target on 69 minutes and then, moments later, Grant made a terrific one-handed save from Henderson's header after a Taylor free-kick.
Esajas was proving to be a big threat and he fired just wide of the angle of crossbar and post on 76 minutes with a first time effort and then struck another into the arms of Bunn soon after.
Cotterill was booked for a foul on Spurr in the final five minutes as nerves became even more frayed. Quinn became United's second substitute and Bunn collected an Esajas free-kick.
On 89 minutes a powerful shot from Evans was tipped over by Grant and from the corner the Wednesday goalkeeper gathered in a powerful Morgan header. The Blades skipper was booked for deliberately slowing down the action.
Five minutes of added time gave Wednesday further hope and Walker was forced to cut out a cross destined for Esajas. Blackwell used the last of his replacements with France taking the place of Cotterill.
The final moments were nail-biting - for both sets of players, management and fans - but the Blades deservedly held on to present Kevin Blackwell with his first Steel City derby win as United boss.
Blades: Bunn, Montgomery, Morgan, Henderson, Evans, Harper, Taylor, Ward (Cotterill 33, France 90), Davies, Treacy (Quinn 88), Walker.
Unused: Reid, Bennett, Stewart, Little.
Owls: Grant, Spurr, Buxton, Purse, Tudgay, Potter, Wood, O'Connor (Miller 78), Varney (Clarke 67), Johnson (Esajas 45), Gray.
Unused: McAllister, Sodje, Simek, O'Donnell.
