The Clarets showed they are prepared to scrap their way, as well as try and play their way, out of the Championship as they hung on tenaciously with ten men to earn a valuable point in the Lions' Den.
Brian Laws' battlers played almost the entire game a man down after Clarke Carlisle was controversially sent off for a foul on Theo Robinson after just seven minutes.
It was the Clarets' third dismissal on the road this season and with Andre Bikey also succumbing to an early injury, it left a makeshift defence to hold the fort against a Millwall side desperate to celebrate their 125th anniversary with a win.
Their party threatened to be spoiled when Jay Rodriguez scored his first goal away from Turf Moor when he nodded home in the 22nd-minute.
And although Scott Barron levelled shortly afterwards, the Clarets refused to buckle again as they threw up a wall of white shirts to earn the result that kept them in the play-off zone.
The game couldn't have started in worse fashion for the Clarets as they had barely drawn breath when Bikey collided with Steve Morison to collect the rib injury that would force him off.
And within minutes Carlisle's afternoon was over when he mis-timed a challenge on Robinson right on the touchline and gave the opportunity to referee Keith Stroud to stun the Clarets and their captain by flourishing a red card.
Clarke Carlisle is stunned to see red
Laws immediately re-organised as he sent on Michael Duff in place of the unfortunate Dean Marney and handed the skipper's armband to Wade Elliott.
And within five minutes the Burnley boss had been forced into a second change as Leon Cort replaced Bikey to make his first Championship appearance of the season against the club where he started his career.
The Clarets could already have been behind as Robinson headed tamely at Brian Jensen from the first of a series of dangerous crosses from Chris Hackett.
Then as Burnley's new-look defence tried to settle, Alan Dunne dragged a shot just wide as another Hackett cross was only half cleared.
But the home side was rocked after 22 minutes when the Clarets grabbed the lead.
Chris Eagles and Tyrone Mears engineered the opening following a throw-in from Mears and when Eagles swung over a deep cross, Rodriguez showed great strength to head home his second goal of the season.
Jay Rodriguez heads the Clarets in front
With a numerical disadvantage the Clarets needed to protect that lead for as long as possible but within four minutes they had allowed the Lions to level.
After over-playing at the back and surrendering possession, Morison crossed for Robinson to head down and Barron swept the ball home from 12 yards to end the Clarets' run of four successive clean sheets.
Not surprisingly, the Clarets were then forced to defend for long periods with little respite as Chris Iwelumo was asked to forage on his own up front.
But they went into the break at 1-1 thanks to a superb save from Jensen as he plunged to his left to keep out a downward header from Dunne.
The Lions' full-back carried a regular threat on his forays forward and 13 minutes into the second half he rose again with captain Paul Robinson, who got the final touch to another Hackett cross with a header which hit the foot of a post.
It was last-ditch stuff at times from the Clarets but they stuck doggedly to their task and Jensen stood firm again 19 minutes from the end when local hero Neil Harris was presented with a shooting chance with his first touch after coming off the bench.
The Clarets celebrate going ahead
Cort's desire to try and make a block saw the big defender go down with cramp in both legs but he was soon back in the fray and with tired bodies all over the place Laws made his one remaining change with 13 minutes to go as Steven Thompson came on for Iwelumo.
Millwall kept pressing and Danny Schofield though he had scored the winner only for Jensen to finger-tip his curling shot onto the bar.
And with Duff, Cort and the rest of their colleagues manfully giving every ounce of effort the Clarets stoically held on for a draw which might even have been an unlikely win had the tireless Eagles managed to wrap his foot further round an injury-time effort which flew past the post.
Burnley: Jensen, Mears, Fox, Bikey (Cort 14), Carlisle, Cork, Marney (Duff 9), Elliott, Eagles, Iwelumo (Thompson 77), Rodriguez. Subs: Alexander, Wallace, Paterson, Grant.
Millwall: Forde, Dunne, P Robinson, Hackett, Craig (Schofield ht), Barron, Mkandiwire, Ward, Morison, T Robinson (Harris 69), Abdou (Carter 79). Subs: Carter, Henry, Smith, Laird.
Referee: Keith Stroud
Sent off: Carlisle 7
Booked: Burnley: Eagles 43
Millwall: Craig 43, Dunne 48
Attendance: 12,330 (away 842)
Chris Eagles and Jack Cork battle for a point