Millwall were predictably a threat at set pieces and the giant Jake Cooper proved a big problem, the centre-back providing a headed assist from a free-kick for Japhet Tanganga to net the only goal of the game five minutes before the break.
Leeds huffed and puffed and joy turned to dismay midway through the second half when Joel Piroe thought he had drawn his side level, only to be greeted by an offside flag. Whites boss Daniel Farke then threw on an array of forwards but only the frame of the goal denied Millwall a second goal from a set piece as Mateo Joseph’s attempts to clear a Cooper header bounced back off the post.
Leeds needed to win to climb back into the division's automatic promotion places after Tuesday night's victory for Sheffield United at Bristol City but the Whites now remain third, two points behind the Blades and now four pints behind leaders Sunderland.
Victory for Millwall also sent the upwardly mobile Lions into fifth and now just four points behind Leeds who are only three points ahead of fourth-placed Burnley who also have a game in hand.
Graham Smyth, the YEP’s chief football writer, hands out the scores from a night to forget at The Den.
13. Patrick Bamford (sub)
N/A - Tried to cause problems for the centre-backs but wasn't much of a factor beyond one touch that set up a shot for Piroe. Photo: Ryan Hiscott
14. Mateo Joseph (sub)
N/A - Other than heading against his own post he was unable to bring anything to the game in the late stages. Photo: Lewis Storey
15. Leigh Doughty (referee)
4 - Gave some really soft free-kicks for both sides. Failed to get a grip on time wasting. Photo: Alex Davidson