Two goals from Billy Sharp, who has now scored seven times in six starts against his former club, ensured Sheffield United won this crucial Yorkshire derby against Leeds.
Pierre-Michel Lasogga equalised for the visitors, playing their first game under new manager Paul Heckingbottom, at the beginning of the second-half.
But Sharp, after claiming his 200th career league goal in memorable fashion before anyone had broken sweat, reached 201 when John Fleck was sent tumbling in the penalty box.
Chris Wilder's side, who climbed to seventh in the table ahead of the afternoon games, were forcced to survive a period of pressure after Lasogga's intervention, secured the victory they so desperately needed to breathe fresh impetus into their promotion challenge. Leeds, meanwhile, were left to reflect upon another display which, despite troubling United for a brief period, left plenty to be desired.
"We'll keep on believing until someone tells us it's not possible," Sharp, the United captain, said. "We've got a good squad. You've seen that and the character out there."
Uncoverted balls across the opposition's box has been a feature of United's play in recent weeks which, as results faltered, inevitably prompted questions about Sharp's ommision from the starting eleven. It took him less than two minutes to provide the most emphatic of answers; powering an unstoppable finish past Felix Wiedwald and into the back of Leeds' net. The technique was superb and the celebration a release for weeks of pent-up frustration. It was a joyous moment for Mark Duffy too who, later firing over the crossbar as United went in search of a second, had also returned to the team following a period on the bench.
With Duffy tormenting Leeds' rearguard - and the visiting defenders apparently powerless to deal with him - Wilder will been urging his players to make their advantage pay. When they failed, Lasogga made sure they paid the ultimate price by restoring parity. His header, threaded past Jamal Blackman's outstretched palm, was all about placement. The German's intervention changed not only the scoreline but also the pattern of the game, with substitute Pablo Hernandez, whose introduction was forced by injury, providing Leeds with more purpose and guile. At least until Sharp restored United's lead from the penalty spot.
United had triumphed 2-1 at Elland Road earlier this season with Sharp scoring an early goal against his former club before David Brooks' late winner. Although Brooks missed this game as he continues his recovery from glandular fever, Sharp did feature and ensured the return fixture began in similar fashion by scoring his 10th of the season with less than two minutes on the clock.
The strike, arguably his most impressive of the campaign so far, signalled the beginning of a frantic period of football which saw United push hard for a quick-fire second. They nearly achieved their aim when Duffy sliced over the crossbar and Sharp went close again, this time with a close-range header.
Duffy, twisting and turning, was causing Leeds all manner of problems and, after Lasogga had drilled wide for Heckingbottom's men, carved another superb chance. Checking his run before slipping a reverse pass towards Sharp, Leon Clarke was inches away from getting what would have been a decisive touch.
As the half progressed, so Leeds heads began to clear with Ezgjan Alioski becoming more of an influence. And so it proved when, two minutes after the re-start, he dragged Leeds level when United, given their dominance before the interval, will have been disappointed not to have already made the game safe.
Jack O'Connell made a crucial block to prevent Matthew Pennington's shot testing Blackman soon after while, at the other end, Duffy cut inside before firing just over the bar with Wiedwald beaten. Sharp, though, restored United's advantage when the faintest of touches from Eunan O'Kane was enough to send John Fleck, travelling at speed, tumbling. Clarke sliced high and wide following a scramble in the box.
Sheffield United: Blackman, O'Connell, Stearman, Basham, Stevens, Baldock, Evans (Lundstram 88), Fleck, Duffy (Leonard 77), Sharp (Holmes 90), Clarke. Not used: Donaldson, Wilson, Lafferty, Eastwood.
Leeds United: Wiedwald, Forshaw, Pennington, Roofe (Hernandez 44), Lasogga, Alioski (Sacko 75), De Bock, O'Kane, Dallas, Jansson, Phillips (Ekuban 77). Not used: Lonergan, Anita, Cibicki, Viera.
Referee: Andrew Madley (West Yorkshire).