Sheffield Wednesday slipped to a second successive defeat as high-flying Huddersfield emerged with all three points at Hillsborough.
First half goals from Graham Carey and Anthony Pilkington did the damage and despite a revival after the break, the Owls could not breach the Terriers' goal and missed the chance to leapfrog Lee Clark's second-placed side in the League 1 table.
Wednesday made three changes from the side that lost at Charlton on Saturday, with Darren Purse, Chris Sedgwick and Jermaine Johnson all starting the game.
But it was the visitors that threatened first, with Jordan Rhodes inches away from getting something on a close range diving header three minutes in.
The Owls responded with Marcus Tudgay lifting a header on to the roof of the Kop net as the derby contest unfolded at a healthy pace.
The action promptly returned to the other end, though, and Huddersfield came within a whisker of taking the lead on 18 minutes.
The lively looking Rhodes broke free down the right side of the penalty area and unleashed a thunderbolt strike that rattled the post and ran to safety.
But five minutes later, the West Yorkshire outfit got their noses in front. Huddersfield won a free kick 25 yards from goal and up stepped Carey to plant an accurate curling drive away from Nicky Weaver and into the back of the net.
Wednesday were undaunted and pressed forward, with Johnson - making his first start of the season - causing problems in the Terriers' defence.
It was the Owls' pace ace that came close to an equaliser on the half-hour mark after dribbling past two defenders but keeper Ian Bennett came to the rescue with a smart save.
And that served as the ideal platform for Huddersfield to counter and double their lead on 34 minutes. Rhodes led the charge upfield and fed Pilkington, who cut in from the right to execute an unstoppable effort past Weaver.
That second strike knocked the wind out of Wednesday as half time approached and the interval could have been all the more miserable had Rhodes profited from eight yards instead of firing across Weaver and out for a goal kick.
Alan Irvine made a double substitution for the start of the second half, with Clinton Morrison and James O'Connor replacing Marcus Tudgay and Darren Potter.
And the Owls started brightly after the restart. O'Connor tested Bennett with a daisycutter before Morrison went close at the near post from Johnson's teasing cross.
Johnson then blasted an angled shot wide as Wednesday continued to turn the screw but the Terriers' rearguard held out to keep the Owls at bay.
The more the game progressed, the more home side's frustrations grew and after riding the early second half storm, Huddersfield settled back into their stride, albeit without causing the Wednesday defence any further problems.
The better football came from the Owls, who were unlucky with 12 minutes to go when Neil Mellor smashed just over the bar after an impressive three-man build-up.
Substitute Benik Afobe and Rhodes almost added to Huddersfield's tally in the closing stages and to sum up a bleak night, Wednesday finished the game with ten men when Johnson pulled up with what appeared to be a hamstring injury eight minutes from time.
Owls: Weaver, Buxton, Purse, Beevers, Jones, Sedgwick (Teale 76), Potter (O'Connor 46), Coke, Johnson, Tudgay (Morrison 46), Mellor
Unused substitutes: Jameson, Spurr, Hinds, Heffernan
Huddersfield: Bennett, Peltier, Gudjonsson, Clarke, Kay, Garner (Afobe 64), Pilkington, Johnson, Rhodes, Ridehalgh, Carey (Arfield 71)
Unused substitutes: Colgan, Clarke, McCombe, Croft, Atkinson