Two goals from Jermaine Beckford coupled with a James Vaughan effort have ensured a nervy end of the season for Kenny Jackett's Millwall.
The Lions went into action on Saturday knowing that victory would all but secure their Championship status for another 12 months, but Jackett's men are now anxiously looking over their shoulder at the cluster of clubs below.
Beckford took advantage of an uncustomary blunder by skipper Danny Shittu to score the opening goal on 37 minutes before Vaughan added number two 10 minutes after the restart.
Former Leeds striker Beckford then made the points safe, capitalising on more hesitancy in the visiting rearguard to smash home his second and Town's third of the game just past the hour mark.
Manager Jackett refused to make excuses afterwards saying: "I felt that away from home we have defended better than we did today.
We gave poor goals away, we got caught in possession in our own half too often.
The side lacked energy and sparkle, not necessarily commitment, but certainly sparkle.
From our point of view we still have four games left and the equation does lie with getting a team that has the energy to get the points we need at home.
We have to lick our wounds, make sure we get it right and have a freshness and move on again. I'm obviously concerned, but we have to look forward and focus on our three home games in a row. We must get over today and get over it quickly."
Jackett had been forced to reshuffle his defensive pack with Shane Lowry serving a three match ban after accumulating 15 yellow cards.
Mark Beevers switched to left-back with Martyn Woolford in for the injured Chris Taylor and Shaun Batt replacing Jermaine Easter up front.
The Lions struggled to get out of first gear throughout producing a tired performance.
James Henry did hit the woodwork with a sublime 20 yard freekick in the opening eight minutes and also saw another free-kick from a similar position brilliantly parried by Alex Smithies in the home goal when the score was still at 1-0.
But other than that Millwall disappointingly offered little else as an attacking threat and it was the heroics of David Forde at the other end who prevented Town scoring more than just the three goals that they did.
Forde had already made a fantastic block to deny Beckford when Town took the lead. There looked to be minimal danger when Shittu, appearing to have the situation under control, tried to shepherd the ball out for a goal-kick under pressure from Beckford.
The Lions skipper would 99 times out of a 100, successfully see the ball over the line or pass back to keeper Forde to clear. Unfortunately he dwardled enabling Beckford to nick the ball off his toe and then fire home from an acute angle.
Matters went from bad to worse for the visitors when Vaughan added number two in the 54th-minute with a composed finish barely seconds after Woolford and Batt had been replaced by Rob Hulse and Easter.
It was effectively game over just seven minutes later when Vaughan's through ball was picked up by Beckford and he produced a top class finish to fire home number three.
That left the weary Lions with a mountain to climb but aside from Easter scooping the ball over from close range, Jackett's men could not muster any chances to test Smithies in the home goal as Huddersfield secured a win that boosted fresh life into their battle against the dreaded drop.
Huddersfield Town: Smithies, Woods, Gerrard, P.Clarke, Hunt, Scannell, Gobern, Norwood, Clayton; Beckford (Southern, 68mins), Vaughan (Novak, 76mins). Subs not used: Bennett, Lee, Danns, Wallace.
Scorers: Beckford (37, 62mins), Vaughan (55mins)
Millwall: Forde, A.Smith, Shittu, Osborne, Beevers, Henry, J.Smith, Abdou, Woolford (Huklse, 54mins), Keogh (Feeney, 84mins), Batt (Easter, 54mins), Henry. Subs not used: M.Taylor, Dunne, Wright, Saville.
Bookings: A. Smith, Batt, Easter
Ref: S. Mathieson