Millwall got the Championship campaign off to a perfect start as goals in either half from Mark Beevers and a Shaun Williams penalty saw off Leeds United at The Den.
After six weeks and three days of a tough, at times relentless, pre-season training, Ian Holloway's men were raring and ready to go against a United outfit that has suffered well-documented off-field difficulties during the summer.
New United boss Dave Hockaday endured a miserable introduction to life in the Championship as his side were swept aside by a buoyant Lions team featuring debutant Ricardo Fuller and a 'second' debut for right-back Carlos Edwards, who signed a permanent move in the summer following a successful loan spell at the end of the 2013/14 campaign.
Fellow summer signings Lee Gregory, Matthew Briggs, Byron Webster and Magaye Gueye were all named amongst the subs, although there was no placing in either Leeds starting XI or on the bench for former Lion Steve Morison.
The game was played against a backdrop of raucous noise from The Den faithful, all with a real sense of optimism about the season ahead, and by the end of 90 minutes and three points in the bag, it proved justified.
Millwall started on the front foot and broke the deadlock with just eight minutes on the clock. A well-worked corner routine played short by Martyn Woolford to Lee Martin saw the latter's cross pick out Beevers, who slid home to send the home fans wild.
It could have been 2-0 just before the quarter hour with centre half Beevers causing problems again, this directing his header from Woolford's inswinging corner just off target.
Leeds tried to get some rhythm into their play and it took the quick reaction of Lions keeper David Forde to avert the danger on 27 minutes, racing off his line to gather Stephen Warnock's threaded through pass as it headed into the path of Souleymane Doukara.
The visitors nearly capitalised on a rare lapse of concentration in the home defence, but Luke Murphy contrived to drag his shot horribly wide of the target.
However it was Millwall who finished the first 45 minute as they started it, pegging Leeds back deep in their own half.
Alan Dunne was a whisker away from adding a second goal in the 44th-minute when Edwards' dinked free-kick picked out the skipper, and his crisp header was superbly caught at full stretch by keeper Marco Silvestri.
Fuller lashed a ferocious first-time volley over moments later from 20 yards, but Ollie's men had to be content with a 1-0 lead as they headed off down the tunnel.
The second-half started at a rip-roaring pace and it was Leeds who spurned a glorious chance to haul themselves level straight from kick-off, but the trusty figure of Dunne was on hand to clear off the line from Noel Hunt, who really should have levelled with the goal at his mercy.
That sparked an immediate response from Millwall. Woolford's surging run into the danger zone saw the wideman progress to within 10 yards of goal where he let fly with a thumping shot that Silvestri did well to parry. The ball spun up and when it dropped to Jimmy Abdou, he was unable to keep his follow-up shot on target and the ball sailed over the bar.
Millwall had what looked like a stonewall penalty turned down on 59 minutes. Woolford teased and tormented the Leeds defence as he weaved his way into the penalty area where he was sent sprawling by a desperate outstretched leg. It was a big call, but referee Oliver Langford waved play on to the disbelief of the home fans.
Leeds introduced 6' 7" striker Matt Smith and the former Oldham man was left holding his head in his hands after directing a header narrowly wide moments after entering the fray.
The Lions themselves continued to ask questions of the visitors as the game started to open up; Scott McDonald's shot held at the second attempt by Silvestri, who looked on with a sense of relief as a lofted effort from sub Jermaine Easter dropped a yard off the mark.
It took a marvellous one-handed save from Forde to keep out sub Dominic Poleon's goalbound effort as Leeds began to push on in increasing numbers in th final quarter of an hour.
But Millwall had the perfect response and took the wind right out of Leeds sails with three minutes remaining. Sub Lee Gregory was shoved over in the penalty area by Lewis Cook and up stepped Williams to clip home the resulting spot-kick into the bottom left corner beyond the keeper's reach.
Hockaday's side tried to find a way back into the game, but the damage was well and truly done as The Lions saw out four minutes of injury time comfortably to get the season off to a perfect start. Three points. Happy days.
Millwall: Forde, Edwards, Dunne, Beevers, Malone; Williams, Abdou; Woolford (Easter, 66mins), McDonald, Martin (Gueye, 66mins); Fuller (Gregory, 80mins). Subs not used: Bywater, Briggs, Webster, Wright.
Leeds United: Silvestri, Byram, Warnock, Austin, Pearce, Murphy, Hunt (Smith, 57mins) , Wootton, Ajose (Poleon, 76mins), Tonge, Doukara (Cook, 64mins). Subs not used: Berardi, Taylor, Killock, Benedicic.
Ref: O. Langford