Substitute Paul Taylor came on at the New Den to inspire Peterborough to a late comeback at Millwall.
The Lions had a two-goal lead with Darius Henderson first setting up Liam Trotter to score in the first half.
After the break, Hamer Bouazza ran on to Henderson's pass inside the area to drive the ball past keeper Paul Jones.
But Taylor turned the game, setting up Lee Frecklington for a superb 72nd-minute goal before scoring himself with a 30-yard equaliser minutes later.
The game's first real chance came when Lions goalkeeper David Forde came for, and completely missed, Grant McCann's cross as George Boyd's angled volley bounced into the ground and back off the post.
Millwall still looked the more threatening, with Posh keeper Paul Jones pulling off fine saves from James Henry, Darius Henderson and Bouazza.
Yet he could do nothing to prevent the opening goal as an unchallenged Henderson took a couple of touches inside the area before squaring for Trotter to sidefoot home from 10 yards.
The hosts doubled their lead in the 55th minute thanks to another slick move and some non-existent marking. Bouazza was given too much space in the area after Henderson played him in and he blasted the ball into the corner of the net.
But 23-year-old striker Taylor, who was making only his fourth appearance since joining from Anderlecht last season, set up Frecklington to drive home from the edge of the box.
After Trotter cracked a shot against the post as Millwall looked for a third, Taylor stole possession midway inside their half before striding forward to thump a low equaliser past Forde.