Keeper David Forde was the hero with a 90th-minute penalty save from Huddersfield's David Unsworth as Millwall produced a rousing performance to clinch their first League One win of the campaign.
The Lions had already shown their battling qualities, turning a 1-0 deficit into a 2-1 lead with goals from Tresor Kandol (37mins) and Lewis Grabban (62mins) when referee Keith Hill awarded a highly contentious penalty in the dying seconds.
Up stepped veteran defender Unsworth, and the former Everton full-back who is usually so clinical from the spot, was left hanging his head in horror as Forde dived low to his right to smother the spot-kick and spark scenes of wild celebration amongst The Den faithful.
Make no mistake, this was a game that Millwall were forced to dig deep both physically and mentally against a robust Huddersfield side that finished with five men in the referee's book.
It had all started so promisingly for the Yorkshire outfit and they nearly opened their account on eight minutes when a long throw from Nathan Clarke was flicked on to Danny Cadamarteri 14 yards out. The former Bradford City striker chested down before unleashing a fierce volley that whistled too close to the home goal for comfort.
The Lions failed to heed this early warning and when Clarke launched another rocket throw after 17 minutes, Dickinson produced a stunning overhead finish from 12 yards that gave Forde no chance.
Cadamarteri, who had been causing a few problems on the right, hobbled off injured shortly after and it was The Lions who slowly but surely began to take charge of proceedings.
Teenage debutant Karl Moore produced a couple of mazy runs that had the home crowd on their feet, Jimmy Abdou saw his goal-bound header appear to be punched clear by a stray Huddersfield hand and then Chris Hackett's deep 34th-minute free-kick was inches away from Kandol as Millwall started to turn the screw.
The Hackett-Kandol combination came up trumps just two minutes later when the former's delicious deep delivery was headed home by Kandol from close range.
Millwall could have stolen the lead in first-half injury time when Neil Harris and Grabban created an opening on the right and Harris' cross was met by Tony Craig, whose bullet header flashed inches over.
Spurred on by some tremendous support, The Lions picked up where they left off at the start of the second-half with Grabban increasingly influential on the right and linking up extremely well with Hackett.
A great reverse pass from Grabban nearly produced a second goal for Kandol nine minutes after the restart, only for the big frontman's effort to be blocked by Matt Glennon in the visiting goal.
Grabban's pace and close control was causing all sorts of problems to the visiting defence and he again worked an opening for Kandol just before the hour mark, but on this occasion the effort was blocked for a corner.
Young striker Grabban got the goal his effort deserved on 62 minutes. Kandol fed Harris on the right and he slipped the ball through to Grabban, who swept home with aplomb for his second goal of the season.
The Lions continued to tease and torment Huddersfield and twice Harris came close to increasing the lead, firstly after 69 minutes with a close range header that was held by keeper Glennon, and on 74 minutes, when he fired wide following a sensational run down the right by Grabban.
Chopper thought he had put the result beyond doubt - in fact everyone in the ground thought he had - six minutes from time with a clipped angled shot that somehow hit the inside of the right post, trickled along the line and hit the other post before keeper Glennon claimed the ball.
The drama was not over by a long way and as the match was entering the final minute and that first league win of the season was within touching distance, Michael Collins comically stumbled into the area, more in hope than expectation.
To the incredulity of everyone, a spot-kick was awarded and a yellow card brandished to Tony Craig.
But justice was seen to be done when the rotound Unsworth stepped up to take the penalty, only to be thwarted by the athleticism of keeper Forde.
Even then there was still time for Huddersfield to nearly nick an equaliser following an almighty scramble deep into injury-time, but The Lions rear-guard stood firm - and three most welcome points were in the bag.

Millwall: Forde, Hackett, Frampton, Craig, Robinson, Whitbread, Abdou, Moore (Martin, 76mins), Harris, Kandol, Grabban. Subs not used: Edwards, Spiller, Fuseini, Brkovic.
Bookings: Frampton (71mins), Craig (90mins), Martin (90+4mins)
Scorers: Kandol (37mins), Grabban (62mins)

Huddersfield Town: Glennon, Holdsworth, Lucketti, Unsworth, N. Clarke, Roberts, Craney, Worthington (Collins, 60mins), Flynn, Dickinson, Cadamarteri (Parker, 19mins (Jevons, 68mins)). Subs not used: Smithies, T. Clarke.
Bookings: Dickinson (27mins), Worthington (60mins), Lucketti (73mins), Flynn (73mins), Roberts (82mins)
Scorer: Dickinson (18mins)

Ref: Keith Hill
Att: 7,513 (away 488)