In a game of few chances, a moment of quality from Juniniho Bacuna ensured Huddersfield move up to eighth while Derby remain just above the drop zone.
Story of the game
Derby started the better of the two sides, despite being without starman Wayne Rooney having to isolate. Fullback Max Bird cut in off the right and looked for the top corner, however his effort whistled just over the bar.
Andre Wisdom then had an effort from range but Richard Stearman was able to get his body in front of the shot to make the block.
Town however rid the storm and had a good spell of possession without really creating a key chance. Derby's low block meant the ball was often ending up with Pipa and Harry Toffolo on the flanks who had no choice but to throw it in the box but Curtis Davies and Wisdom were able to cope with little stress.
Derby had a penalty claim after 22 minutes, Huddersfield giving the ball away just inside their half. Derby pounced and the ball came to Wales international Tom Lawrence who dinked the ball over the leg of Stearman going down but referee David Webb was having none of it.
Rams tails were up and they had the best chance of the game moments later. Polish winger Kamil Jozwiak cutting in from the left and unleashing a fierce shot across Ben Hamer's goal which had the Town goalkeeper worried.
Pipa was Town's biggest threat in the first half overlapping down the right. He had their first chance of the game, stinging the palms of David Marshall in the Derby goal from a tight angle.
The half then became marred with stoppages and fouls, with the only shot of note in the lead up to half time a shot from Andre Wisdom which was straight at Ben Hamer.
Lawrence looked to be in through the middle moments later but the flag quickly went up as he looked to slot past Hamer. The former Leicester man looked the biggest threat to the Huddersfield defence, looking to get on the turn against Naby Sarr.
Huddersfield's only shot in the final twenty minutes was a shot from Pipa which flew straight over the bar.
As the half time whistle blew, it had been a disappointing first half. The game had been overly scrappy, with mostly half chances being created by both sides. Neither goalkeeper had been tested and both sides needed to seriously improve in the second half.
Town came flying out the traps and should have taken the lead within two minutes of the restart. Toffolo with good work down the left putting an excellent low ball in which Campbell just needs to get a touch on, but on the stretch he couldn't connect.
Josh Koroma then went on an excellent run into the Derby box, but young academy graduate Lee Buchanan came across to snuff out the danger.
Huddersfield were able to hit the front after 52 minutes. They played out from the back through the Derby press, Toffolo breaking down the left cut it back behind the the run of Fraizer Campbell to Juniniho Bacuna who hit it first time into the bottom left corner beyond Marshall from the centre of the box.
It was a great move by Huddersfield and will please coach Carlos Coberhan who encourages Town to play out from the back and through the press. The speed from which they transitioned from Hamer into attack and carved open Derby showed the confidence within the side.
Straight after the goal, Huddersfield brought on Christopher Schindler to sure up their defence and make it harder for Derby to play through the middle. The Rams had lacked any real width in attack and looked as if their only hope of scoring was set pieces.
Town were still a threat, Koroma in particular the main threat. His quick feet and trickery allowed him to get into the Derby box but he was unable to work an angle to shoot and Campbell was crowded out by Derby defenders when the ball rebounded to him.
Derby had a good chance after 76 minutes. Nathan Byrne down the right with good work, cut it back to former Huddersfield man Duane Holmes but his side foot effort was a comfortable save for Hamer.
Huddersfield happy with their one goal lowered the tempo, rarely overcommiting in attack. Their best chance late on came from a freekick. Naby Sarr's header having to be tipped over by David Marshall and the resulting corner came to nothing.
Derby went down with a whimper, their delivery from set pieces in particular left a lot to be desired. They had most of the possession in the final minutes but were unable to find any gaps that would create a chance.
Full Time: Huddersfield Town 1-0 Derby County
Huddersfield XI: Hamer(GK), Pipa (Duhaney, 79) , Stearman, Sarr, Toffolo,Bacuna,Hogg (c), Eiting (O'Brien, 64) , Mbenza (Schindler, 54) , Campbell, Koroma
Subs: Pereria(GK), Brown, Pritchard, Diakhaby
Derby XI: Marshall (GK), Byrne, Davies (c), Wisdom, Clarke, Buchanan (Kazim-Richards, 79) , Bird, Shinnie (Waghorn, 62) , Knight, Lawrence (Holmes, 62), Jozwiak
Subs: Hector-Ings (GK), Roos, te Wierik, Forsyth
Man of the match: Harry Toffolo
More often than not when Harry Toffolo plays, you can be sure of one thing, he will give an 8/10 performance. His energy down the left hand side is key to the way Huddersfield play. He should have had an assist at the start of the second half for Campbell but he got his assist eventually for Bacuna. Against Nathan Byrne who loves to attack, he made sure he got the better of the battle.
Huddersfield are learning
To the untrained eye, Huddersfield's goal was well worked but to both fans and Carlos Coberhan it was huge. It's the first time Town have scored as a result of playing out of the back. From the first game to now Huddersfield have took huge strides and if they can continue to be sound at the back and find the net Coberhan's tactics could pay off.
Derby are in trouble
Derby clearly have the players to push for promotion but tonight they didn't turn up. Lawrence had his moments but they were short lived. If it wasn't for a moment of Rooney magic they would be pointless. It’s unlikely that they will be in the relegation dogfight but they need to improve quickly. Their set piece delivery in particular tonight was not good enough.