Wednesday put ten-man Leeds to the sword on Saturday at Hillsborough with an emphatic 6-0 win.
It was a dominating performance from start to finish from Wednesday, who were simply too good for United on the day.
First half goals from Reda Johnson and Atdhe Nuhiu sent the Owls into the break two goals to the good.
Leeds striker Matt Smith was introduced from the bench for the start of the second period but left the action just seconds later, picking up a straight red card for a clash with Reda Johnson.
The ten men of Leeds were facing an uphill battle that became even steeper when Connor Wickham fired home his eighth goal in ten games.
The visitors' misery was compounded when Chris Maguire’s deflected free kick nestled in the back of the net but there was more to come.
Caolan Lavery, fresh from his productive loan spell with Plymouth, added a fifth ten minutes from time and scored the Owls' sixth in added time to cap an excellent day for the hosts.
The early stages were typical of a derby affair with strong challenges flying in from the off, as Lee Peltier produced a crunching challenge on Jose Semedo in the opening minute.
And after enjoying the best of the early action, the Owls edged in front with a superbly worked goal finished off by Reda Johnson.
Following a half clearance from Leeds, Kieran Lee chipped a delicate ball into the middle for the defender, who composed himself before lifting the ball over Paddy Kenny and into the Leppings Lane net.
Still the Owls continued on the front foot and Wickham sent a glancing header wide before Kenny was called into action to save a stinging Maguire drive at the near post.
Things got even better for Wednesday right on the stroke of half time with Nuhiu on target for his third goal of the season.
Wednesday broke in numbers as Wickham played in Lee, who advanced into the box before squaring for Nuhiu to slide in at the back stick.
The Owls were relentless going forward and Liam Palmer had a golden chance to make it three before the break but clipped inches wide, with Wednesday well in the driving seat.
The second half began with an extraordinary piece of action just seconds after the restart.
Smith, who had just been introduced to the action, received a straight red card for a dangerous challenge on Reda Johnson having only been on the field for a matter of seconds.
And to add to Leeds’ misery, Wednesday effectively killed off the game minutes later.
Wickham picked up possession just outside the area and cleverly advanced with the ball before beating Kenny at his near post with a low strike.
It was becoming a long afternoon for United, who looked out of sorts at Hillsborough, but there was no let up from the Owls as the one-way traffic continued.
Wednesday looked like adding to their lead with every attack and in the 66th minute, it was 4-0 with Maguire inking his name on the scoresheet.
The Scot lined up a free kick from 25 yards and his low strike flew past Kenny, who remained rooted to the spot with the ball taking a deflection along the way.
There was still time for more punishment, though, as the rampant Owls hit their fifth goal ten minutes from time.
Lavery, recalled from Plymouth in midweek, picked up possession on the halfway line and advanced towards Leeds’ goal with menace before tucking his strike neatly into the net off the post.
The youngster was on target again in added time, profiting from another Leeds mix-up at the back and firing home into the bottom corner - the day well and truly belonged to Wednesday.
Owls: Kirkland, Palmer, Llera, Loovens, R Johnson, Lee, Semedo, Maghoma (J Johnson 74), Maguire (Helan 81), Wickham, Nuhiu (Lavery 66)
Leeds: Kenny, Peltier, Lees (Smith 46, sent off 46), Pearce, Austin, Pugh, Zaliukas, Stewart, Mowatt, Kebe, McCormack