Leeds put their midweek thrashing by Nottingham Forest behind them by moving to within three points of the play-offs thanks to a gutsy win at Millwall.
Ross McCormack struck from close range for his first goal in eight matches to give Leeds the lead.
A minute later, Andy Lonergan saved a Darius Henderson penalty after Alex Bruce felled Millwall's Andy Keogh.
Millwall skipper Paul Robinson had a late chance to snatch a point, only for his header to hit the bar.
Robert Snodgrass set the tone for a feisty affair in the opening seconds with a fierce challenge which left Jack Smith in a heap on the touchline, earning the Leeds skipper a booking.
Harry Kane and Henderson went closest for Millwall in a forgettable first half, while McCormack had a goal disallowed for offside.
But Leeds improved after the break, a clever flick from Luciano Becchio putting McCormack through, only for the striker to shoot too close to Lions keeper Maik Taylor.
The visitors finally made the breakthrough in the 65th minute when Snodgrass surged down the right and crossed for McCormack to scramble the ball over the line.
Millwall were handed a lifeline moments later when Bruce upended Keogh inside the box.
Kane fired the loose ball into the net but the referee had already awarded the spot-kick, and Henderson's shot was superbly turned away by Lonergan.
The result means Millwall are still without a home win this year.