Full-time from Calmont Road
Millwall's U21s battled back from a 2-0 deficit to record an excellent win against 10-man QPR.
The west London side looked to be in complete control as they roared into a two-goal lead with just five minutes on the clock.
But Aiden O'Brien reduced the arrears and then levelled from the penalty spot with his second goal of the game.
Peter Skapetis was dismissed before half-time for the visitors and The Lions took full advantage of their extra man, adding further goals from Charlie Penny and Niall McManus to wrap up victory.
It had all started so well for R's who stunned Millwall with two goals in less than 80 seconds.
There were just four minutes on the clock when Skapetis stole in to plant a firm header beyond the reach of Denzil Gerrar following a Jay Gibbson delivery.
Moments later Michael Petrasso picked up a loose ball and rifled into the far corner to put QPR 2-0 ahead.
But in a lively opening, The Lions soon reduced the arrears with O'Brien racing clear of a static defence and planting a low shot under Joe Lumley in the visiting goal.
Millwall came close to levelling midway through the half when Penny forced a fine save out of the keeper, whilst at the other end Gerrar's hands were stung by a fierce shot from Mo Shariff.
Play swung from end to end, but it was Millwall who scored next when O'Brien levelled from the penalty spot after a handball in the area.
Rangers were rocking now and having let a two-goal lead slip, they then found themselves at a numerical disadvantage just before half-time when goalscorer Skapetis was shown a straight red card for violent conduct.
In a breathtaking first 45 minutes there was still time for Millwall's Sid Nelson to have an effort cleared off the line as the two teams went in level at the break.
The visitors had a penalty appeal waved away moments after the restart when Shariff's shot seem to hit a stray hand, but the incident was unsighted by the officials.
QPR continued to press forward, despite being down to 10 men, but it was Millwall who got their noses in front with 14 minutes remaining courtesy of Penny's smart finish following a quick counter-attack.
In a real ding-dong encounter back came the visitors once again and the home side had a lucky let-off just three minutes later when Cole Kpekawa's curling free-kick smacked against the crossbar before the ball was cleared.
Midfielder McManus put the result beyond doubt late on, however, tapping home from close range to put the seal on a battling display by the young Lions.
Millwall: Gerrar, Siafa, Bender, Powell, Nelson, De Havilland (Farrell, 65mins), McManus, Simpson (Thompson, 71mins), O'Brien, Onyedinma (Philpot, 90mins), Penny. Subs not used: Goodman, Twardek.
QPR: Lumley, Gibbons, Monthe, Laurent, Brown, Kpekawa, Shariff (Balanta, 69mins), Carreiro, Hitchcock, Skapetis, Petrasso. Subs not used: Smith, Furlong, Mitchell.