This was billed as master versus pupil, and without a doubt Neil Warnock handed out a harsh lesson to Kevin Blackwell on the realities of life in the Football League.
Blackwell spent 17 virtually-unbroken years working under Warnock as player, coach and then assistant manager, the latter with Sheffield United before an acrimonious parting of the ways last summer.
Warnock claims he was informed of Blackwell's departure to Leeds as head coach via a journalist, resulting in the two once-close friends not speaking to one another for many months.
Their differences have since been resolved, yet Warnock can now happily claim to have had the last word as his own United brushed aside that of Blackwell's in a sombre, almost passionless Yorkshire derby at Bramall Lane.
Two goals in 12 second-half minutes from veteran striker Ashley Ward and winger Jon Harley settled this encounter, lifting Warnock's Blades into eighth in the Coca-Cola Championship on the back of what is now two successive victories.
For Blackwell, it is a meagre five points from five matches, although since an opening day home victory over Derby, Leeds have found life uncomfortable in this league following their relegation from the
Premiership in May.
Leeds are certainly lacking in quality, and on the evidence of this performance, they are also missing certain other key ingredients to survive at this level such as a degree of understanding between one another, invention and creativity.
There is little cohesion, perhaps understandable when you consider Blackwell has had to completely rebuild the squad, but after six matches in total under his tutelage, Leeds are not showing too many signs of improvement.
After a woeful first-half in which Andy Gray wasted three chances to break the deadlock, and former Blades striker Brian Deane became a target for the home faithful after scuffles with Leigh Bromby and Chris Morgan, the game finally came alive in the 50th minute.
Michael Tonge's through ball was perfectly weighted, splitting the Leeds defence and leaving 33-year-old Ward - currently with his 11th club of a 15-year career - to coolly slot his 110th league goal past a wrong-footed Neil Sullivan.
It required a fingertip save from Sullivan to deny skipper Morgan his side's second from a powerful header five minutes later, but there
was little the Scotland international could do about the goal which sealed the three points.
When Gray was felled by Duberry, who was wrongly booked in the first half for a sliding challenge on Harley, it allowed the latter to tee up a 30-yard free-kick which he planted with some aplomb into the top left-hand corner.
That was effectively game over as, despite Blackwell starting with all three available strikers in Deane, Michael Ricketts and Julian Joachim, Leeds barely threatened the Blades goal.
Frazer Richardson had one shot saved by a full-stretch Paddy Kenny at the end of the first half, and Duberry struck the bar from two yards out in the 76th minute, apart from which the result was never in doubt.
Ward could have rubbed salt in Blackwell's wounds eight minutes from time, but again the woodwork proved the difference as his header to a Harley cross struck the bar.
There were chants of 'easy, easy' from the home fans once the final whistle sounded and Warnock's side are gathering momentum.
Leeds, with no goals in six matches from their strikers, could find themselves in the bottom three by the end of tomorrow's Bank Holiday fixtures as Blackwell is discovering just how tough it is to manage one of the country's biggest clubs.