Millwall's miserable run at The Den continued as 10-man Huddersfield edged to a victory that left The Lions without a home win in nine games.
It had looked so promising for Ian Holloway's side as they battled back from Sean Scannell's 17th-minute strike to level through Stefan Maierhofer (28mins) and were then handed a numerical advantage following Nakhi Wells' dismissal early in the second-half with the score at 1-1.
However individual errors by Jimmy Abdou and then Shaun Williams were ruthlessly capitalised on, enabling Chris Powell's side to secure all three points with further goals from Jacob Butterfield (74mins) and a James Vaughan penalty (86mins) respectively.
It was a bitter pill to swallow as The Lions' hopes of building on a mini revival that had seen the team draw 0-0 with Reading and then win 1-0 at Nottingham Forest, were dashed.
Millwall lined up showing just one change to the team that started at the City ground last time out with winger Lee Martin (ribs) replaced by Ed Upson. New loan signings Michael Tonge and Jordan Archer were on the bench.
The Lions mustered the first scoring opportunity of the game after six minutes with a rasping drive from Magaye Gueye that was smartly saved by Alex Smithies in the Town goal.
Millwall maintained the early pressure and were denied the opening goal on 12 minutes when Maierhofer's angled snap-shot from Upson's pass smacked the outside of the Huddersfield post.
It was Huddersfield, however, who took the lead against the run of play as Scannell latched onto Well's lobbed through ball, beat the offside trap and hit a rasping shot beyond the reach of keeper David Forde.
Roared on by the home fans The Lions kept prising and probing and hauled their way back onto level terms just 11 minutes later. Shaun Williams whipped in a deep free-kick from the right, Mark Beevers' header was blocked by Smithies and the ball ended up in the back of the net via Maierhofer, who was in the right place to get the final touch.
Winger Scannell, a constant threat throughout, nearly capitalised on hesitancy from Beevers but thankfully blasted the ball into the side netting and moments later threaded the ball through to Harry Bunn, whose effort hit the bar.
There were no changes by either team at the break, but there was numerically within four minutes of the re-start when Wells, already on a final warning having been booked in the first-half, was shown a second yellow card for a clumsy challenge on Williams leaving Millwall with an extra man.
Despite upping the pressure, The Lions could not find a way through with Maierhofer inches away from connecting with Jos Hooiveld's cross and then Upson lashing the ball narrowly over from 18 yards.
However, an unfortunate slip by Abdou on 74 minutes handed the visitors an opportunity to take the lead - and they gratefully accepted. Abdou slipped on a greasy surface and despite getting a toe to the ball, inadvertently diverted straight into the path of Butterfield who strode forward before hitting a long-range shot that bounced over Forde and into the net.
It was game over six minutes from time when Bunn weaved his way into the penalty on the left, was caught by the boot of Williams and referee Mike Jones pointed straight to the spot. Vaughan made no mistake, sending Forde the wrong way with a crisp finish into the bottom right corner to kill off any hopes of a late Lions fightback.
Millwall: Forde, Cummings, Beevers, Hooiveld, Dunne, Williams, Abdou, Fabbrini, Upson (Gregory, 68mins), Maierhofer (Fuller, 68mins), Gueye (Woolford, 77mins). Subs not used: Archer, Webster, Harding, Tonge.
Upson (22mins), Forde (23mins), Williams (30mins)
Smithies, Edgar, Hudson, Scannell, Butterfield, Vaughan (Miller, 89mins), Coady, Wallace, Robinson, Wells, Bunn (Gobern 90+2mins). Subs not used: Allinson, Colley, Wilkinson, Wright, Majewski.
Butterfield (23mins), Wells (31mins), Wallace (55mins), Edgar (56mins)
Scannell (17mins), Butterfield (74mins), Vaughan (86mins, pen)
Ref: M Jones
Att: 10,281 (away 586)