A last-minute try from Kurtley Beale denied Wales victory over old foes Australia as the Gold run continued with a 14-12 result on Saturday.
The loss meant that Wales, the current Grand Slam champions and World Cup semi-finalists, fell out of the top-eight seeds for RWC 2015, the draw for which takes place on Monday.
The game had looked to be going Wales' way at 12-9 with a minute to play, but replacement flanker Dave Dennis found a metre of space out wide with the Welsh defence flagging and fed Beale, who outpaced Alex Cuthbert to the corner.
It was a ninth victory in 15 Tests of a marathon season for Australia and meant they leapfrogged South Africa into second in the IRB rankings.
But the defeat was Wales' seventh on the trot and denied them the chance of a first win over a southern hemisphere nation since their 2008 victory over the same opposition.
Leigh Halfpenny kicked four penalties for Wales, who had lost November matches against Argentina, Samoa and New Zealand, with Beale notching up three of his own for the visitors.
Beale missed two other penalty attempts and replacement Mike Harris another in the sixth match between the two sides in 13 months, the Wallabies winning all five previous encounters, including the third-place play-off at the World Cup and a closely-fought three-Test series on Australian soil in the summer.
Beale missed a straightforward early penalty attempt as referee Wayne Barnes took to his whistle against a series of sloppy Welsh ruck infringements.
The visitors, fielding just three players from last year's season-ending victory in Cardiff, dominated early possession and territory, but it was Wales who first set the stadium alight when Cuthbert was set free on his own line.
A fine covering tackle by Berrick Barnes smothered Cuthbert into touch.
Beale was successful with his second penalty, struck from the halfway line, and Halfpenny responded almost immediately with his own 52-metre effort.
The Welsh full-back then pushed the home side into the lead with a second penalty in the 23rd minute after returning Wallaby openside David Pocock was penalised for not rolling away in the tackle.
Halfpenny then split the defence and while he collided with Barnes chasing his own chip ahead across the line, Toby Faletau crashed through, only to be beaten to the ball by opposite number Wycliff Palu.
Beale drew the scores level with a second long-range penalty but failed with an easier effort that would have seen the Wallabies into the lead.
Wales, with fly-half Rhys Priestland showing signs of his old confidence, looked to run everything, but Australia showed why they remain in the top three countries in the world with an aggressive, counter-rucking defence.
The Wallabies ended the half 9-6 up after Beale nailed his fifth attempt at goal after home captain Sam Warburton was penalised, again at the ruck, while Halfpenny sent a late effort wide.
The second period opened with a full seven minutes of aerial ping-pong, neither side able to capitalise on any real territorial gain.
Halfpenny, comfortably Wales' best player in the four November Tests, was on hand to again show his defensive abilities with a fine covering tackle with Ryan Jones on Drew Mitchell, who should have gone wide after a Barnes feint.
The Welsh full-back finally drew Wales level on 55 minutes with a penalty after the Wallaby scrum wilted and then put Wales into the lead when Australia captain Nathan Sharpe, playing in his 116th and final Test, was found on the wrong side of a ruck.
Replacement Mike Harris then saw his penalty drift wide as the Wallabies tried to find a way through the Welsh defence, which finally flagged when Dennis found Beale who finished excellently in the corner.
Man of the match: We go for Leigh Halfpenny after another impressive performance at the back for his country. He was yet again faultless covering the ground in attack and defence while his kicking from hand and tee means that he edges out Wallaby flank David Pocock.
Moment of the match: Of course, that last-gasp try from Kurtley Beale.
Villain of the match: Nothing too dirty to report.
Pen: Halfpenny 4
Pen: Beale 3
Wales: 15 Leigh Halfpenny, 14 Alex Cuthbert, 13 Jonathan Davies, 12 Jamie Roberts, 11 Liam Williams, 10 Rhys Priestland, 9 Mike Phillips, 8 Toby Faletau, 7 Sam Warburton (c), 6 Aaron Shingler, 5 Luke Charteris, 4 Lou Reed, 3 Scott Andrews, 2 Matthew Rees, 1 Gethin Jenkins.
Replacements: 16 Ken Owens, 17 Ryan Bevington, 18 Samson Lee, 19 Ryan Jones, 20 Justin Tipuric, 21 Tavis Knoyle, 22 Dan Biggar, 23 Scott Williams.
Australia: 15 Berrick Barnes, 14 Nick Cummins, 13 Adam Ashley-Cooper, 12 Ben Tapuai, 11 Drew Mitchell, 10 Kurtley Beale, 9 Nick Phipps, 8 Wycliff Palu, 7 David Pocock, 6 Scott Higginbotham, 5 Nathan Sharpe, 4 Kane Douglas, 3 Ben Alexander, 2 Tatafu Polota Nau, 1 Benn Robinson.
Replacements: 16 Stephen Moore, 17 James Slipper, 18 Sekope Kepu, 19 Dave Dennis, 20 Michael Hooper, 21 Brendan McKibbin, 22 Mike Harris, 23 Digby Ioane.
Referee: Wayne Barnes (England)
Assistant referees: Romain Poite (France), Greg Garner (England)
Television match official: Marshall Kilgore (Ireland)