Millwall's automatic promotion hopes suffered a setback as Peter Clarke's 39th-minute header sent Kenny Jackett's side spinning to only their second defeat in 20 games.
The Lions did everything but score as they battered Lee Clark's outfit in the second half, but just could not find that killer touch in front of goal.
Midfielder Marc Laird was handed his first League start of 2010, replacing the injured Liam Trotter who picked up a hamstring injury at Yeovil Town on Tuesday.
With Chris Hackett in for Neil Harris, The Lions showed two changes to the side that started against Yeovil.
However, within just four minutes Jackett was forced to shuffle his playing pack once again.
Following a swift counter-attack, Shaun Batt's involvement in the evening's proceedings come to an abrupt halt when he hobbled off after appearing to overstretch trying to reach the ball.
Jon Obika came on and nearly put The Lions ahead a couple of minutes later with an angled left-foot drive that flew a yard wide following Jimmy Abdou's slide-rule pass.
A great turn and touch from Steve Morison saw the Lions striker break free in the danger zone before he seemed to be held back by Peter Clarke as he prepared to shoot, but referee JJ Linington waved away appeals for a penalty.
At the other end Theo Robinson hit a low drive straight into the grateful hands of keeper David Forde with the home side's first shot on target after 25 minutes before Hackett's deep delivery was clawed out of the air at the far post by Alex Smithies in the Town goal.
Hackett was again involved on the half-hour mark when his firm left-foot drive was deflected for Millwall's only corner of the half.
Town were inches away from breaking the deadlock when a swift counter-attack ended with Jordan Rhodes contriving to scoop wide from seven yards following a blistering run from Robinson.
But just two minutes later the home side did open the scoring when skipper Clarke rose highest to head home from Daniel Drinkwater's corner six minutes before the break.
For the second time in four days The Lions found themselves trailing at half-time, but unlike Tuesday night at Yeovil when they struggled for long spells, Jackett's side came out firing on all cylinders after the restart and skipper Paul Robinson was unlucky to see his header from a Hackett corner blocked with Millwall's first clear chance of the half.
However The Lions had a lucky let-off on 52 minutes when Theo Robinson got behind the visiting defence and with Forde caught in no man's land, the Town frontman despatched a lob from 25 yards that dropped just wide of the post.
Neil Harris was introduced shortly after and it was from his great cross from the right that Laird's diving header flashed a yard wide with keeper Smithies rooted to the spot.
Millwall began to turn the screw and a huge punt up field by Forde was headed on to Harris, whose low delivery flew agonisingly across the face of goal with no fellow Lion on hand to connect.
Jackett's men kept their foot on the gas, and grew in confidence as the game progressed with Huddersfield visibly wilting under the sustained onslaught of possession and pressure.
Morison's goalbound shot was blocked, and when a delicious delivery from Smith was met by Obika, the striker saw his towering header smack the woodwork as Millwall tried to get back on level terms.
The late introduction of Gary Alexander for Morison was the last throw of the dice for Millwall, and when Peter Clarke caught Tony Craig with an elbow in the dying seconds the defender's penalty appeal fell on deaf ears once again, you just sensed it was going to be one of those nights.
Unfortunately The Lions simply could not produce that one moment of magic to salvage a point, and must now hope that the three remaining fixtures reap nine points - and a couple of defeats for Leeds, Charlton and Swindon too. In no particular order!
Huddersfield Town: Smithies, T.Clarke, Trotman, P.Clarke, Peltier (Williams, 82mins), Roberts, Kay, Drinkwater, Pilkington, Rhodes (Novak, 63mins), Robinson (Berrett, 90+2mins). Subs not used: Eastwood, N.Clarke, Pearce, Eccleston,
Bookings: P. Clarke (60mins), Roberts (80mins)
Scorer: P.Clarke (39mins)
Millwall: Forde, Smith, Craig, Abdou, Robinson, Ward, Schofield, Laird, Morison (Alexander, 82mins), Batt (Obika, 4mins), Hackett (Harris, 54mins). Subs not used: Sullivan, Barron, Grimes, Fuseini.
Booking: Smith (27mins)
Ref: JJ Linington
Att: 16,050 (away 827)