Substitute Mathias Jorgensen scored twice in the final 10 minutes as Blackburn boosted their survival hopes in the Sky Bet Championship with a vital 2-1 victory at promotion-chasing Millwall.
Middlesbrough's draw against Bristol City earlier on Saturday gave the Lions the chance to move into the automatic promotion places and they looked to be heading there thanks to Luke Cundle's spectacular opener.
But a red card for Millwall defender Zak Sturge changed the contest dramatically as Rovers produced a late comeback that moved them three points clear of the relegation zone.
It took 23 minutes for the first decent effort from either side as Taylor Gardner-Hickman's free-kick needed tipping over by Millwall goalkeeper Anthony Patterson.
This led to Blackburn being the first to settle and they missed a great chance to go ahead when Eiran Cashin met Todd Cantwell's cross with a header that drifted wide.
The home fans, knowing the opportunity the Lions had been presented with, were growing increasingly restless at their side's sluggish performance, which showed little sign of improving.
Millwall failed to have a shot in the first half, but they were nearly ahead four minutes after the restart when Femi Azeez's cross was cleared as far as Barry Bannan, whose effort was pushed behind by Blackburn goalkeeper Balazs Toth.
It did not take the Lions quite as long to have their second attempt as, a minute later, Camel Neghli's lovely ball into the box was headed over by captain Jake Cooper.
A half-time talking-to had clearly done the trick for the hosts, who led after 54 minutes when Azeez's cross was met by a superb overhead kick from half-time sub Cundle that nestled in the bottom corner.
A chance to double the lead on the counter soon came along as Josh Coburn's pass sent Neghli galloping towards the area, but his shot across goal went narrowly wide.
Then came a big twist as Millwall went down to 10 men in the 59th minute when Sturge was shown a straight red for pulling down Yuki Ohashi as he was trying to run through on goal.
Thrown a lifeline, Rovers went on the attack with Ryan Alebiosu having a shot saved by Patterson, but the Lions were a threat on the break as Azeez fired narrowly over from a tight angle.
Blackburn had their equaliser in the 80th minute when Ohashi's pass put Alebiosu in behind and his ball across the six-yard box gave Jorgensen the simplest of tap-ins.
And a dramatic late turnaround was completed five minutes later when Ryoya Morishita's pass found Jorgensen in space and the Dane swept his shot into the bottom corner to give the visitors a priceless victory.
Millwall's Alex Neil:
"I don't think it's a sending-off. We've got Jake [Cooper] covering. It was shoulder-to-shoulder with Jake initially, Zak then tries to get back round him and doesn't try to foul him, he tries to sort of just jump over his leg and come back round because the lad cuts him off.
"Then we've got Camiel Neghli recovering but, more importantly, the lad's touch takes him away from goal initially. We've got three covering defenders and the ball is about 25-30 yards out.
"If you're going to take your next step into the box to potentially shoot unopposed, my understanding of the rules is that's then a goalscoring opportunity.
"I don't think he would have got that far to get there and get that opportunity to score, so in my opinion I didn't think it was a sending-off.
"That then impacts the game but even then, I thought we did really well."
Blackburn's Michael O'Neill:
"Alex has built a strong team here with a lot of physical presence that can really test you, and we had to match that in the early part of the game.
"I thought we did that and I thought we played some excellent football as well without maybe having the cutting edge. We probably could have been better in the final third.
"Then, when we went behind, obviously the reaction we got was superb and we scored two very good goals. We then saw the game out and it was a massive three points."
