Millwall and Leeds are now three points off the play-off places after a hard-fought draw at the New Den.
Millwall defender Paul Robinson scored his first League goal for the club after 17 minutes, bundling the ball home from close range.
But Rob Hulse secured a point for Leeds with a neat turn and shot into the bottom corner 12 minutes from time.
Both sides could have had penalties in the second half, while Millwall's Josh Simpson somehow missed from a yard out.
Millwall boss Dennis Wise confirmed afterwards that he had gone into the crowd at half-time to confront a Lions supporter.
"There were a couple of fellas in the stand who always seem to want to give the players stick and they normally start the other fans off.
"So I just went up to one of them and said 'look, get behind the lads. I've got a lot of kids out there and it's hard for them. This is the last thing they need'.
"He was fine with that. He shook my hand and that was that. I wasn't afraid to go up to him. What was he going to do? Punch me?"
Millwall boss Dennis Wise on the game:
"I'm proud of them, they showed a lot of enthusiasm and did extremely well.
"They don't know the game properly yet and need a bit of help but you can expect them to always work hard and they showed what they can do.
"I thought we were hard done by and did enough to win the game but we're still in with a shout."
Leeds boss Kevin Blackwell:
"This period of the season is not for the faint-hearted and the play-offs is now only a win away.
"We didn't start as well as we have done of late but we were much better in the second half.
"We've come a long way since the start of the season and, form-wise, from November we are second in the league so we had to give it a go."
Millwall: Marshall, Paul Robinson, Lawrence, Ward, Craig, Sweeney (Weston 84), Elliott, Morris, Simpson, Quigley (Peeters 89), Dichio.
Subs Not Used: Serioux, May, Stack.
Booked: Elliott.
Goals: Paul Robinson 17.
Leeds: Sullivan, Kelly (Carlisle 90), Butler, Kilgallon, Gray, Lennon, Walton (King 60), Gregan, Derry, Healy (Johnson 84), Hulse.
Subs Not Used: Wright, Pressman.
Booked: Gregan, Derry.
Goals: Hulse 78.
Att: 11,510.
Ref: B Knight (Kent).