Sean O'Brien was the match-winner as Millwall's Under 23s defeated Sheffield Wednesday 1-0 in the Professional Development League on Tuesday afternoon.
The attacker took advantage of a loose ball in the box to tap home the only goal of the game and give Paul Robinson's side the victory at Bracken Moor.
Ciaran Brennan saw red for The Owls in the second-half, whilst Billy Mitchell completed 75 minutes on his comeback from injury.
O'Brien had three attempts blocked by the Wednesday defence and an inspired Josh Render in goal, but was fourth time lucky as he opened the scoring on 77 minutes. Shortly before that, Brennan was given his marching orders by the referee for bringing down George Alexander when on goal.
Next up for Millwall's Under 23s is a home game with Crewe Alexandra next Tuesday afternoon.
Millwall: Wright, Moss, Topalloj, Strachan, A. Mitchell, Muller, Skeffington, B. Mitchell (Allen 75'), Alexander, O'Brien, Davis (Boateng 46'). Subs not used: Gillmore, Abdulmalik, Penney.