Scott Malone struck a crucial last-gasp leveller as Millwall grabbed a draw from the jaws of defeat at promotion-chasing QPR.
Charlie Austin, who so famously missed a sitter for Swindon in the 2010 Play-Off Final for Swindon against Millwall, looked to have gained sweet revenge when he calmly slotted home a 75th-minute penalty after sub Simeon Jackson was penalised for handball.
But left-back Malone hit would could just be the goal that keeps Millwall in the Championship with a deft chip deep into injury-time that was palmed into the back of his own net by Hoops keeper Robert Green.
With fellow strugglers Blackpool picking up a shock 2-0 win at Wigan, but Birmingham, Charlton and Doncaster all losing, The Lions simply could not afford to lose, and dug deep to make it seven games unbeaten with Bournemouth at home next Saturday the season's final fixture.
Boss Ian Holloway made one change to the team that started against Doncaster earlier in the week, bringing back Owen Garvan in place of Scott McDonald after the midfielder had missed Monday's game through illness.
The Lions produced some delightful controlled football in the opening half and could have taken the lead after just two minutes when Garvan's deep cross from the left was met by the head of Stefan Maierhofer, but he glanced his header off target from eight yards.
Carlos Edwards then squared for Shaun Williams, who fired over before the right-back then picked out Lee Martin on 11 minutes, the latter sending a bouncing effort narrowly wide of the post.
Martin then set up Maierhofer with another inviting delivery headed wide by the big Austrian, but the flying winger had his contribution to proceedings cut short just past the quarter hour mark when he was stretchered off with a badly gashed knee making a brave block tackle.
On came Steve Morison and The Lions picked up where they left off with Maierhofer planting a header narrowly off target once more in the 19th-minute.
QPR offered very little in a disappointing opening half from the hosts and it took until 27 minutes for Lions keeper David Forde to be called into action, collecting Niko Kranjcar's delivery under pressure following a short corner.
Maierhofer saw his audacious 45-yard lob drop onto the roof of the net with Green flapping at thin air as Millwall continued to look the more likely of the teams to score, but The Lions had Forde to thank for keeping it at 0-0, brilliantly tipping over Ravel Morrison's bullet header in first-half injury-time.
Forde then so nearly turned provider, picking out Martyn Woolford with a huge goalkick racing down the right flank. Woolford shrugged off the challenge of Richard Dunne but then drove a yard wide with the goal begging.
QPR came out showing greater urgency after the restart and the teams traded scoring chances; Malone firing wide from distance and then Tom Carroll firing narrowly over from 25 yards out.
Holloway brought on Jackson and McDonald for the tiring Maierhofer and Garvan, and Jackson twice wasted good opportunities, lashing the ball wide as The Lions produced a couple of quick counter-attacks.
At the other end Austin was well marshalled by Alan Dunne and Mark Beevers, but there was little either defender could do to prevent him opneing the scoring just 15 minutes from time. Jackson was penalised for handball on the edge of the penalty area and referee Kevin Friend pointed straight to the spot, from which Austin made no mistake.
Millwall were agonisingly close to grabbing an 85th-minute equaliser when Shaun Williams sublime curling free-kick smacked the woodwork and was gathered by the keeper under pressure from McDonald.
Williams went close with another free-kick from a near-identical position just a couple of minutes later, this time Green plucked the ball out from under the bar as it headed towards the top right hand corner.
Time looked to be running out for Millwall, but these Lions do not give up without a fight and when Malone charged forward again in support of the attack, he picked up the ball 18 yards out, dinked a shot that took an eternity to go goalwards and was then palmed, slow-motion-like, into his own net by Green to spark wild celebrations by the travelling fans.
There were barely seconds remaining and when referee Friend blew for full-time to leave The Lions hanging on to their Championship survival dream with one game to go.
QPR: Green, Simpson, Dunne, Hill, Onuoha, Carroll, Barton, Kranjcar (Zamora, 74mins), Benayoun (Hoilett, 63mins), Austin (Doyle, 83mins), Morrison. Subs not used: Murphy, Yun, Hughes, Henry.
Austin (78mins, pen)
Millwall: Forde, Edwards, Malone, Beevers, Dunne, Bailey, Williams, Martin (Morison, 16mins), Garvan (McDonald, 65mins), Woolford, Maierhofer (Jackson, 53mins). Subs not used: Bywater, Robinson, Abdou, Easter.
Bookings: Beevers (60mins), Forde (70mins)
Scorer: Malone (90+4mins)
Att: 15,725 (away 1,367)