Two superb second-half goals from Martyn Woolford (65mins) and Scott Malone (76mins) made it a hat-trick of wins as Millwall continue to climb the Championship table with an excellent victory against Leeds United.
Following a pretty uneventful opening 45 minutes the introduction of substitute Lee Martin sparked the game - and The Lions - into life.
It was Martin who fashioned a slide-rule pass for Woolford to produce a delightful finish for the opener and then Malone struck a sweet second goal following excellent play from Liam Trotter to double Millwall's tally.
Millwall boss Steve Lomas was forced to make a couple of changes to the team that beat Charlton last Saturday with Scott McDonald (knee) and Mark Beevers (knee ligaments) both sidelined, whilst loan striker Steve Morison was not eligible to play against his parent club.
In came Danny Shittu for Beevers and Jermaine Easter for McDonald, the latter playing at the top of a front three flanked by Woolford and Waghorn.
Danny Shittu returned to Millwall's starting line up in the absence of the injured Beevers, whilst Easter came in for McDonald after the striker failed to recover from a knee injury picked up against Charlton.
Leeds went close to breaking the deadlock with just two minutes on the clock when Rodolph Austin capitalised on a moment of hesitancy in the home defence and sent a fizzer from 16 yards a foot wide of the far post.
However it was Lomas' charges who came closest to scoring on 28 minutes when a slick move involving Easter and Trotter played in Waghorn, whose rasping angled drive smacked the foot of Paddy Kenny's far post with Woolford firing the rebound over the bar from eight yards.
Millwall were denied what looked like a nailed-on penalty just before the break when, minutes after Shittu had headed wide from Waghorn's corner, the rampaging Malone was sent sprawling by Austin as he prepared to pull the trigger six yards out.
At the other end there was a collective sigh of relief from The Den faithful when Jason Pearce ballooned over the bar barely four yards out with the visitors' best chance of the half.
Millwall came flying out of the traps after the break and could have scored just 60 seconds into the second period only for Trotter to fire over from a central position after the ball fell kindly to him.
Leeds responded and it was more by luck than judgement that Ross McCormack's glancing effort from an Alex Mowatt cross flew a whisker wide of the post.
Boss Lomas introduced for Martin for Easter six minutes later, with Waghorn moving 'up top', the sub using his pace to torment Stephen Warnock on the right enabling Woolford to weave his magic on the left.
And it was Martin who created the opener with an incisive through pass that cut through the Leeds defence like a knife through butter, picking out the run of Woolford, who steadied himself before firing into the bottom corner past the outstretched hands of keeper Paddy Kenny.
With The Den faithful now in full voice and the team in full flow, The Lions went close to doubling their tally on 67 minutes when Martin was again instrumental in setting up Waghorn, but the striker hesitated just as he was about to shoot with just Kenny to beat, and had the ball nicked off his toes by a covering defender.
Millwall did, however, grab the second goal that their pressure deserved - and what a cracker it was once again! This time Trotter and Malone played a succession of one-twos with left-back Malone finally planting a sweet finish into the back of the net to send the home crowd wild.
Malone then so nearly turned those cheers to jeers with what would have been a bizarre own goal moments later when his over-hit back pass caught goalkeeper David Forde off guard. Malone chased back cleared the ball against the post and into the arms of the grateful keeper.
Forde was called into action seven minutes from time when Austin latched onto McCormack's pass, but the Republic of Ireland stopper bravely smothered the midfielder's effort. He injured himself in the process, but to chants of 'Fordey, what's the score?' from the Dockers Upper, managed to respond despite being flat on the floor and receiving treatment!
Millwall so nearly put the icing on the cake right at the death when Trotter's inch-perfect through ball sent the impressive Woolford clear through, but his chipped effort over the advancing keeper Kenny came agonisingly off the woodwork once again.
Despite not scoring a third goal, it was another job well done for The Lions, who were excellent value for their first Saturday win at The Den since December 2012.
Millwall: Forde, Malone, Robinson, Shittu, Abdou, Bailey, Trotter, Waghorn (Keogh, 83mins), Easter (Martin, 51mins), Woolford. Subs not used: Bywater, Connolly, Osborne, Chaplow, Derry.
Booking: Martin (72mins)
Scorers: Woolford (65mins), Malone (76mins)
Leeds United: Kenny, Peltier, Pearce, Murphy, Austin, Varney (Smith, 70mins), Warnock (Green, 79mins), Tonge (Byram, 79mins), Wootton, Mowatt, McCormack. Subs not used: Hunt, Diouf, Poleon, Cairns.
Booking: Warnock (17mins)
Att: 13,063 (away 2,081)