The Wallabies have stunned Wales, coming back from 21 points down to win 39-34 in Cardiff
The visitors' fate looked sealed when the hosts raced out to a 34-13 lead with 25 minutes to go.
Two yellow cards on either side of half-time left the depleted, tired and battered Wallabies out on their feet.
However, the hallmark of Dave Rennie's tenure has been their fight as Player of the Match Mark Nawaqanitawase got the Wallabies back in the contest with two quick tries.
A Penalty try and a second yellow card to Wales set up the grandstand finish before Lachlan Lonergan latched onto a loose ball to score the winning try.
“It was a game around momentum,” Wallabies coach Dave Rennie said after the game.
“They got it early, pressure resulted in a couple of cards. I thought we got fantastic impact off the bench who we went to early and we had all the momentum late in the game and applied pressure through there.
“Huge amount of ticker in this group and we had a number of guys who played in the Italy game who had a chance at redemption. There were a number of young guys who really fronted today.
“We’re stoked. It’s a nice way to finish off.”
It was all Wales in the opening 55 minutes as they took advantage of a disjointed Wallabies defensive line.
Legendary lock Alun Wyn Jones proved his class in the tenth minute, turning playmaker to put Jac Morgan over after breaking through the line.
As both sides traded penalties, number eight Taulupe Faletau celebrated his 100th game in style as he dived over in the corner, allowing the hosts to take a quick 20-6 lead.
The visitors settled into the contest and built some pressure via some solid breaks from Len Ikitau and Mark Nawaqanitawase.
They eventually found their way over the line via the rolling maul and Folau Fainga’a.
Dave Rennie’s men were forced to dig deep when Jake Gordon was yellow carded for a professional foul, falling to get back onside after a Rio Dyer break.
With Tom Robertson sent to the bin shortly after the break for too many scrum penalties, Wales looked to have sealed the win when Morgan crossed for his second, followed over by Dyer for a 34-13 lead.
But inch by inch, play by play, the Wallabies fought their way back into the contest.
The interjection of Pete Samu was game-changing as his grubber put Wales under pressure, flipping field territory and possession to allow Nawaqanitawase to strike in the corner.
Eight minutes later, Samu snatched an intercept and attempted to race away, stopped by the errand leg of Wales captain Justin Tipuric, tripping the back-rower.
This reduced the hosts to 14 and accelerated the visitors' momentum, who seemed to find a second wind in attack.
A well-worked line-out move put Nawaqanitawase over for his second, reducing the margin to just nine.
The visitors followed this up with a dominant rolling maul with six minutes remaining, earning the penalty try and a yellow card to Ryan Elias.
This set up another grandstand finish as both sides showed their desperation to claim a much-needed win.
Nawaqanitawase produced another bit of magic to find space, putting the visitors on the attack.
A looping ball from Len Ikitau found the hands of a Welsh defender, spilling it in the process.
This paved the way for Lachlan Lonergan to dive over the line, giving the Wallabies an unlikely lead with 90 seconds to go.
In true Wallaby fashion, there was one twist late as referee Matthew Carley found a late penalty with seconds remaining.
Asked to defend their line one last time, Lonergan proved the hero once again, coming up with the steal and booting the ball out to seal a famous victory
TRIES: Morgan 2, Faletau, Dyer
CONS: Anscombe 4/4
PENS: Anscombe 2/2
TRIES: Fainga'a, Nawaqanitawase 2, Lonergan, Penalty Try
CONS: Donaldson 1/1, Lolesio 2/3
PENS: Donaldson 2/2, Hodge 0/1
WALES v WALLABIES TEAMS
Wales 15 Josh Adams, 14 Alex Cuthbert, 13 George North, 12 Joe Hawkins, 11 Rio Dyer, 10 Gareth Anscombe, 9 Tomos Williams, 8 Taulupe Faletau, 7 Justin Tipuric (captain), 6 Jac Morgan, 5 Alun Wyn Jones, 4 Adam Beard, 3 Dillon Lewis, 2 Ken Owens, 1 Gareth Thomas.
Replacements: 16 Ryan Elias, 17 Rhodri Jones, 18 Tomas Francis, 19 Ben Carter, 20 Josh Macleod, 21 Kieran Hardy, 22 Rhys Priestland, 23 Sam Costelow
Australia: 15 Tom Wright, 14 Jordan Petaia, 13 Len Ikitau, 12 Reece Hodge, 11 Mark Nawaqanitawase, 10 Ben Donaldson, 9 Jake Gordon, 8 Langi Gleeson, 7 Fraser McReight, 6 Jed Holloway, 5 Cadeyrn Neville, 4 Nick Frost, 3 Allan Alaalatoa, 2 Folau Fainga’a, 1 James Slipper (captain).
Replacements: 16 Lachlan Lonergan, 17 Tom Robertson, 18 Sam Talakai, 19 Ned Hanigan, 20 Pete Samu, 21 Tate McDermott, 22 Noah Lolesio, 23 Jock Campbell.
Referee: Matthew Carley (England)
Assistant referees: Luke Pearce (England), Chris Busby (Ireland)
TMO: Joy Neville (Ireland)