Lewis Grabban struck for the second successive match as Millwall dug deep to secure a priceless point in this Kenilworth Road basement battle.
Young striker Grabban, who scored his first goal for The Lions against Port Vale four days ago, headed home a 39th-minute equaliser to cancel out Paul Furlong's 18th-minute opener for Luton Town.
This was not a game for the faint-hearted, with chances created - and missed - at both ends as neither side were able to score that all-important second goal.
Lions boss Kenny Jackett was able to name an unchanged side for only the second time since taking charge at The Den, and his young team came flying out of the traps just as they had against Port Vale at the weekend.
Dave Martin registered the first shot on goal after two minutes when he cut in from the right and saw his effort deflected past the post.
A second Millwall corner three minutes later saw Zak Whitbread's header from a Martin delivery hacked off the line.
Again Jackett's pressed forward in numbers with Gary Alexander the next Lion to try his luck, this time with a 20-yard drive that fizzed narrowly over.
Alexander was in the thick of the action again on 14 minutes with a header from Grabban's cross that he glanced narrowly wide of the mark.
Luton's response was immediate and Lions keeper Rhys Evans did well to keep out Matthew Spring's goalbound header.
Marc Laird was left cursing his luck on 18 minutes when Alexander picked out the midfielder unmarked eight yards out. Although Laird connected,, he sent his downward header straight into the grateful hands of Dean Brill in the Luton goal.
Millwall were made to pay for their profligacy in front of goal seconds later when Furlong used all his experience to escape the attention of Whitbread to plant a firme header home following a superb Dean Morgan delivery.
To their credit, Jackett's men kept their shape and discipline and continued to pile forward at regular intervals.
Grabban was denied a 34th-minute equaliser by the boot of Keith Keane, who just got enough off the ball to deflect the striker's shot behind. Then from Ali Fuseini's resulting corner, Whitbread's powerful header was tipped over acrobatically by keeper Brill.
A good move involving Marcus Bignot and Jay Simpson provided an opportunity for Grabban four minutes later, with the latter's goal-bound effort deflected for a corner as The Lions turned the screw.
Something had to give - and when Martin swung over another corner, Brill flapped at the ball and there was Grabban to take advantage, heading home from close-range.
Millwall could have taken the lead within a minute of the second-half when the dangerous Simpson sprinted down the right, cut in and fired straight at Brill.
At the other end Stephen O'Leary had a great chance for the home side, but with time and space to pick his spot, he fired straight at Evans.
Back came Millwall, this time Alexander steering a Bignot cross wide of the post.
That proved to be the striker's last contribution to proceedings with boss Jackett bringing on Bas Savage and former Luton favourite Ahmet Brkovic for Alexander and Fuseini respectively.
Unfortunately The Lions lost their attacking momentum and it was Luton who began to carve out scoring opportunities.
Spring twice wasted glorious opportunities to put The Hatters ahead, the worst of which came 20 minutes from time when he inexplicably fired wide of an empty net from six yards.
Millwall seemed unusually nervy - and when the fourth official held up the board to indicate five minutes of injury time, there was a collective groan from the travelling fans who couldn't wait for referee Keith Woolmer to blow the final whistle.
Luton came close to grabbing all three points with virtually the last kick of the match - a stinging shot from Spring that Evans could only parry. Thankfully Whitbread produced a perfectly-timed interception to clear the danger with Paul McVeigh ready to pounce.

Luton Town: Brill, Perry, Morgan (McVeigh, 83mins), Bell, Jackson, O'Leary, Emanuel (Goodall, 22mins), Talbot, (Andrew, 80mins), Keane, Spring, Furlong. Subs not used: Charles, Beavon.
Booking: O'Leary (86mins)
Scorer: Furlong (18mins)

Millwall: Evans, Senda, Bignot, Fuseini (Brkovic, 58mins), Robinson, Whitbread, Martin (Forbes, 72mins), Laird, Grabban, Alexander (Savage, 58mins), Simpson. Subs not used: Edwards, Frampton.
Booking: Robinson (26mins)
Scorer: Grabban (39mins)

Ref: Keith Woolmer