Alan Dunne struck a sensational injury-time leveller as Millwall moved back into the Play-Off places with a deserved draw at Walsall.
The Lions received a boost before kick-off when top six rivals Swindon Town were thumped 4-0 at home by Bristol Rovers, with Huddersfield Town then losing 2-0 at Gillingham.
But it looked as if Kenny Jackett's men were going to finish the day in seventh spot as Walsall stole into a 2-0 lead with just 26 minutes gone.
Steve Morison handed The Lions a lifeline on the half-hour mark and right-back Dunne completed a stirring fight-back with a 25-yard piledriver in the dying seconds of the game.
It may have been heartbreaking for Walsall to concede so late - especially having played the final 30 minutes a man short following the sending-off of Matt Richards for two bookable offences - but few in the Banks's Stadium could complain that The Lions were rewarded for incessant second-half pressure.
The game was barely 30 seconds old when Neil Harris latched onto a long punt by Paul Robinson on the right only to be sent sprawling by Richards.
Chris Hackett produced the first of a string of pinpoint deliveries, but his subsequent free-kick was eventually cleared.
Harris again got into a good position, this time on the opposite flank when he collected Tony Craig's threaded pass along the line, however on this occasion Chopper's cross was blocked. The striker then needed lengthy treatment from physio Bobby Bacic after he was caught late by Rhys Weston, but was thankfully able to return to the field of play.
Walsall stunned The Lions on 12 minutes when they broke the deadlock with virtually their first attack of the game.
Liam Trotter was shaping to shoot 20 yards out at one end, lost possession and Walsall's Troy Deeney thumped the ball forward, more in hope than expectation. Alex Nicholls was quick off the mark, latched onto the pass and sprinted forward before rifling a low angled shot into the bottom left hand corner.
The visiting fans had little to cheer about as Jackett's men struggled to make any headway and matters went from bad to worse midway through the half.
Millwall failed to clear their lines following a spell of sustained attacking play by Walsall and Richard Taundry needed no invitation when the ball dropped to him 20 yards out, hitting an unstoppable shot past keeper David Forde.
Millwall needed an early response - and that's exactly what they got just three minutes later.
Former Lion Jamie Vincent and Saddlers keeper Rene Gilmartin hesitated on the edge of the area, and Morison reacted quickly to nip in between the dithering duo and steer the ball into an empty net.
Harris was a foot away from heading The Lions level on 36 minutes, but his effort from Danny Schofield's free-kick dropped wide.
An absolute screamer from Craig smacked the corner of the bar and then Harris glanced narrowly wide following another well-worked set-piece, this time involving Hackett, as The Lions kept the pressure on.
Saddlers defender Marc Richards, already booked for ahigh boot that caught Hackett on the head, escaped with a stern lecture from referee Keith Hill having bodychecked the same player just before the break.
Hackett's dinked delivery from the subsequent free-kick was met by Robinson, with the skipper's effort off the mark as the half came to a close.
Top scorer Harris was perhaps still feeling the side-effects of that challenge early in the match and was replaced by Shaun Batt just three minutes after the restart.
And the sub was a whisker away from scoring with his very first touch, steering a low shot past the post following great work by Hackett.
Schofield hit high and wide and Batt was thwarted by Gilmartin as Millwall pounded the home defence.
Walsall were reduced to 10 men on 68 minutes when Richards again caught Hackett with a clumsy challenge, leaving referee Hill no choice other than to brandish a second yellow card.
Morison nearly made The Lions' numerical advantage count seconds later, only to see his goal-bound header cleared by the towering Clayton Donaldson.
Morison then sent a diving header from Dunne's delicious delivery straight into keeper Gilmartin's hands as Walsall continued to defend resolutely.
Boss Jackett brought on Scott Barron and then Jon Obika in a bid to try and find a way past Walsall's 10 men.
Barron's deep delivery was headed over by Morison from a central position and then Morison again headed wide from Hackett's delivery as Millwall stayed virtually camped in the Walsall half.
For all their possession it looked as if The Lions were going to head home empty-handed until Dunne popped up to secure what could prove to be a priceless point with his magnificent last-gasp strike.
Walsall: Gilmartin, Weston (Westlake, 46mins), Jones (Hughes, 76mins), Deeney, Nicholls (Byfield, 87mins), Taundry, O'Keefe, Vincent, Richards, Gray, McDonald. Subs not used: Ince, Sansara, Bradley, Grigg.
Bookings: Richards (36, 64mins), Nicholls (82mins)
Sending off: Richards (64mins)
Scorers: Nicholls (12mins), Taundry (26mins)
Millwall: Forde, Dunne, Craig, Abdou (Obika, 78mins), Robinson, Ward (Barron, 67mins), Schofield, Trotter, Harris (Batt, 59mins), Morison, Hackett. Subs not used: Sullivan, Smith, Frampton, Laird.
Scorer: Morison (29mins), Dunne (90+3mins)
Ref: Keith Hill