Magaye Gueye’s late strike rescued a point for Millwall as Bournemouth missed the chance to go top.
The Cherries opened the scoring through Steve Cook, who found the net with a header from Andrew Surman’s cross.
Brett Pitman made it 2-0 after latching onto Matt Ritchie’s pass, before Ed Upson’s back-post header pulled one back for the Lions.
Alan Dunne’s header then hit the bar for Millwall, who equalised when Gueye lashed home from inside the box.
The result sees Bournemouth, who had been top at one stage in the afternoon, slip to fourth, two points off leaders Derby, while Millwall are 20th – two points off the bottom three.
Bournemouth dominated the first half at Dean Court with an early Cook header coming before Ritchie’s strike flew just wide of the target.
Yann Kermorgant’s header from Simon Francis’ cross cleared the bar for the Cherries while Pitman saw an effort tipped over by David Forde.
However, their breakthrough came after 22 minutes when Cook’s header back across goal beat Forde for 1-0.
Soon after, Pitman raced onto Ritchie’s throughball and slid under Forde as Bournemouth doubled their advantage.
Millwall came back into the game in the second period with Martyn Woolford nodding wide before Upson pulled one back, heading past Artur Boruc for 2-1.
The Cherries wasted a golden chance to seal the game when Pitman found himself in front of goal. But, rather than slot past Forde, he opted to tee up Junior Stanislas, who found the net but was in an offside position.
And they paid the priced when the visiting team levelled the score, with Gueye firing home in the 88th minute.