The Wallabies were left to lament a lack of execution and poor discipline as their five-match winning streak was brought to a halt by Scotland, a result coach Dave Rennie says his side will simply have to "cop on the chin".
Australia had their chances at Murrayfield, and saw a first-half try overturned because of foul play, but they were largely their own worst enemy inside the final 20 minutes when a lack of accuracy, some loose ball carries and some dogged Scottish defence made the pursuit of victory too great a challenge.
Skipper Michael Hooper rued the loss of the momentum built over the past two months, but still backed his side to bounce back in what will be a huge Test at Twickenham on a six-day turnaround next Saturday.
But Australia will need to rediscover the form that saw them outclass South Africa and Argentina in the Rugby Championship, albeit then with the key backline cogs of Samu Kerevi and Quade Cooper at the Wallabies' disposal.
In Edinburgh, the Wallabies never really settled into the groove like they had done against both the Springboks and Pumas, and instead endured more of the flustered moments they had against Japan a fortnight ago.
"It was a tough game because we just struggled to get things going," Rennie said of the 15-13 defeat. "We got penalised a bit in possession when we thought we had them under pressure and we struggled to get our game going in the last 20 as well.
"They did a really good job at defending the maul, and there were a handful of decisions that we made and maybe the ref made that shaped the last 20. We've got to take it on the chin. We've got to be better, we've got to be better disciplined and we've got to be more accurate."
The Wallabies also found themselves on the wrong end of two key first-half decisions, which saw Scotland awarded a try despite apparent obstruction from a rolling maul, and then the Australians stripped of five points -- and almost certainly seven -- when Allan Alaalatoa was found to have clipped a Scottish player on the chin with a swinging-arm cleanout.
Given the lack of force, Alaalatoa avoided the fate that Sekope Kepu suffered four years ago when he was red-carded at the same venue, but it was still a real momentum-stopper for Australia with Hooper's try scratched from the ledger as a result.
"I'm not one to have a crack at referees around decisions and that sort of thing, but it was a pretty tough decision against us I thought," Rennie said of the Alaalatoa call.
Scotland's own first-half five-pointer, meanwhile, was dubious. Having received a lineout transfer, lock Grant Gilchrist, while in front of try-scorer Hamish Watson, appeared to transfer possession to his teammate before contact had been made with the Wallabies defense, raising the question of obstruction. But referee Romain Poite and his assistants saw it otherwise and upheld the on-field decision of try.
Ruling on maul infringements is never easy, particularly with the shifting bodies and for the fact that the ball is often obscured from view, so it is understandable that Poite, refereeing his last Test, stuck with his original call.
The Wallabies were able to mitigate the loss of Alaalatoa and even scored their only try while the prop was in the sin-bin, a powerful run from debutant replacement Izaia Perese creating the momentum for Rob Leota to then pick a perfect line to bust through from a Nic White pass.
But it was a rare moment of clinical execution from an Australian team which suddenly resembled more of the wayward outfit that was smacked 3-0 by the All Blacks, before the Wallabies embarked on their five-match winning streak.
Having won turnover ball, in the position to put the Scottish defence under genuine pressure, Len Ikitau and Folau Fainga'a looked for the instant miracle pass early in each half respectively instead of consolidating possession and giving the Wallabies the chance to set a platform.
Then later in the game, the Australians were guilty of poor bodyheight which gave the Scottish defenders the opportunity to either hold the Wallabies ball-carriers up, or strip them of possession like they did with Perese on another occasion. It is a tactic European teams have used against Australia for many years now.
Of the latest bunch of the returned Test legion, Rory Arnold got through a solid 50-minute stint before he was replaced by Will Skelton, who only had fleeting opportunities to showcase his destructive ball-carrying.
Given the Wallabies' struggle to really impact the Scots' defensive line and shape, the Leota try aside, Skelton could well find himself in the run-on team at Twickenham. Injuries and concussion uncertainty -- with Jordan Petaia [hamstring], Taniela Tupou and Alaalatoa [both concussion] -- and the six-day turnaround means the selectors have some potentially difficult decisions to make.
But it is not cause for great alarm either.
Sure, the Wallabies will have to improve their execution, discipline and decision-making in London, but to slot this defeat into the "upset" category is a slight on Gregor Townsend's team.
Scotland had more run metres, broken tackles and clean breaks, enjoyed a higher tackle percentage, and they also had the edge at scrum time. They were deserved winners.
And only nine months ago Townsend's team went to London and beat England for a first Calcutta Cup win on English soil in 38 years.
"There has been a calmness around the group for the last two weeks and that is because of players who have evolved over the last few years into leaders, as well as the togetherness of the group and the trust they have in how we want to play," Townsend said of his team's performance.
"I think calmness also comes from belief and we have had some big performances in the last (nine months)..."
But Australia's own Twickenham drought only stretches back to 2015.
The momentum of Australia's five-match winning streak has been halted, no doubt. But it would be restored, and then some, should they notch a first win over England in the Eddie Jones era.
"The whole tour's been pretty large in terms of what we want to achieve up here," Hooper said. "That's a setback today. The motivation was about going really well today and continuing the momentum from the year. We roll now into a six-day turnaround against the English.
"The record hasn't been great, but a lot of these guys haven't played up here, haven't been a part of those games so don't feel that stuff. It's a great challenge for us next week to roll into England. The fire in the belly hasn't distinguished at all. After that, it's just raised."