Match ends, Millwall 1, Leeds United 1.
Jack Harrison's late goal earned Leeds a deserved point at Millwall and extended the Championship leaders' unbeaten league start.
Leeds came closest to scoring in a nervy first half, Ezgjan Alioski heading narrowly wide and Ben Amos saving well to deny Tyler Roberts.
Millwall took the lead when Jed Wallace fired in off the post after the visitors failed to clear a long throw.
Amos reacted brilliantly to keep out Luke Ayling's close-range strike, but he could do nothing to stop Harrison's effort from the edge of the box.
Tom Elliott almost won it for the Lions in added time, his header against the inside of the post deflecting safely away from the Leeds goal.
Millwall also had appeals for a penalty turned down by the referee as Elliott went down in the box, but neither side could complain with the final result.
Leeds had slightly the better of the first-half chances but lacked a cutting edge without injured strikers Patrick Bamford and Kemar Roofe.
Wallace's clinical finish looked to have earned his side a ninth win in 10 home games against Leeds, only for Harrison to respond with his side's first Championship goal at the Den since 2012.
The visitors remain top of the league as a result of Middlesbrough's defeat by Norwich, while Millwall are 19th.
Match ends, Millwall 1, Leeds United 1.
Second Half ends, Millwall 1, Leeds United 1.
Attempt blocked. Jed Wallace (Millwall) right footed shot from the right side of the box is blocked.
Attempt missed. Ryan Leonard (Millwall) right footed shot from the centre of the box misses to the left following a corner.
Attempt missed. Tom Bradshaw (Millwall) right footed shot from very close range is close, but misses to the right following a corner.
Corner, Millwall. Conceded by Stuart Dallas.
Attempt blocked. Tom Bradshaw (Millwall) right footed shot from the centre of the box is blocked. Assisted by Tom Elliott with a headed pass.
Tom Elliott (Millwall) hits the left post with a header from the centre of the box. Assisted by Jed Wallace following a corner.
Corner, Millwall. Conceded by Barry Douglas.
Foul by Barry Douglas (Leeds United).
Tom Bradshaw (Millwall) wins a free kick in the defensive half.
Goal! Millwall 1, Leeds United 1. Jack Harrison (Leeds United) left footed shot from outside the box to the bottom right corner.
Adam Forshaw (Leeds United) wins a free kick in the attacking half.
Foul by Tom Bradshaw (Millwall).
Offside, Leeds United. Barry Douglas tries a through ball, but Liam Cooper is caught offside.
Substitution, Millwall. Tom Elliott replaces Lee Gregory.
Stuart Dallas (Leeds United) wins a free kick on the right wing.
Foul by James Meredith (Millwall).
Attempt missed. Shaun Williams (Millwall) left footed shot from outside the box is close, but misses the top left corner. Assisted by Ryan Leonard.
Foul by Lewis Baker (Leeds United).
Ryan Leonard (Millwall) wins a free kick in the defensive half.
Attempt blocked. Tom Bradshaw (Millwall) right footed shot from the centre of the box is blocked. Assisted by Jake Cooper with a headed pass.
Corner, Millwall. Conceded by Lewis Baker.
Adam Forshaw (Leeds United) wins a free kick on the right wing.
Foul by Lee Gregory (Millwall).
Substitution, Leeds United. Adam Forshaw replaces Kalvin Phillips.
Kalvin Phillips (Leeds United) wins a free kick in the defensive half.
Foul by Tom Bradshaw (Millwall).
Attempt missed. Stuart Dallas (Leeds United) left footed shot from a difficult angle and long range on the right is too high. Assisted by Luke Ayling.
Substitution, Millwall. Tom Bradshaw replaces Steve Morison.
Substitution, Leeds United. Stuart Dallas replaces Tyler Roberts.
Attempt saved. Tyler Roberts (Leeds United) header from the centre of the box is saved in the bottom left corner. Assisted by Samuel Sáiz with a through ball.
Attempt missed. Lewis Baker (Leeds United) right footed shot from outside the box is too high. Assisted by Samuel Sáiz.
Corner, Leeds United. Conceded by Ben Amos.
Attempt saved. Luke Ayling (Leeds United) right footed shot from very close range is saved in the centre of the goal. Assisted by Tyler Roberts.
Substitution, Leeds United. Lewis Baker replaces Mateusz Klich.
Offside, Leeds United. Samuel Sáiz tries a through ball, but Ezgjan Alioski is caught offside.
Jed Wallace (Millwall) is shown the yellow card for a bad foul.
Barry Douglas (Leeds United) wins a free kick in the defensive half.
Foul by Jed Wallace (Millwall).