Tom Leahy's 91st-minute winner secured a 2-1 final-day victory for Millwall's Under 23s over Sheffield Wednesday at The Den on Tuesday afternoon.
Sean O'Brien gave The Lions the lead in the Professional Development League fixture, but after Sam Durrant equalised from range later in the first-half, it seemed as though the game would end in a draw.
Substitute Leahy, however, got his head on the end of a Jayden Davis cross one minute into added time to win the three points for Kevin Nugent's side.
Nugent fielding the usual names of Arthur Penney, Nana Boateng, Abdul Abdulmalik and more for the final fixture of the season.
The opening goal came just nine minutes in - a minute after Kamarl Grant had a header disallowed for offside - as O'Brien flicked home a cross.
Durrant then restored parity by crashing in an effort off the far post from 30 yards out, but Leahy's goal ensured the Under 23s finished the campaign in style.
Millwall: Gillmore, Walker, Adom-Malaki, Smith, Penney, Grant, O'Brien, Davis, Boateng (Leahy 76'), Abdulmalik, Allen. Subs not used: Garande, Hammond, Esse, Cotton.
Scorer: O'Brien 9', Leahy 90+1'
Sheffield Wednesday: Charles, Olurunnisomo, Gavin, Dunn, Agbontohoma, Adentoro, Triveman, Glover, Owoeyo, Durrant, Aguas. Subs: Ham, Ashman, Davidson, Fusire, Flannery.
Scorer: Durrant 36'
Referee: Mr B. Atkinson