The Wallabies' dream of bouncing towards a coveted grand slam of triumphs on their British Isles tour is over, dynamited 27-13 by a buoyant Scotland at Murrayfield.

They were also beaten by the one who got away, with Scotland's Australian captain Sione Tuipulotu powering over for their first of their tries in an inspiring performance in front of his own Glasgow-born gran in Edinburgh on Sunday (Monday AEDT).

Joe Schmidt's men, infused with such high hopes of a first home-nation sweep in 40 years after their thrilling triumphs at Twickenham and Cardiff, found Murrayfield a fortress too far at the end of a trying week.

Even worse, the Wallabies camp were left fretting over the fate of their superstar cross-code centre Joseph-Aukuso Suaalii, who went off clutching his wrist after handing out a big hit on Tuipulotu late in the first half and never returned.

Rarely threatening in attack after putting a combined 13 tries past England and Wales in previous weeks, the Wallabies were contained by a well-drilled Scottish defence until the 75th minute when Harry Potter, with a fittingly magical little juggling act before he touched down, scored on debut.

But the tries from Tuipulotu, a national record-breaking 30th for Ruhan van der Merwe, Josh Bayliss and the ever mercurial Finn Russell, who scored 12 points, were a fair reflection of the Scots' dominance in a brutal reality check for the visitors.

In fairness, things had looked bleak after a difficult week in which they had been unable to prepare properly because of frozen pitches and snow-bound interventions.

And in the 24 hours before the game, they had lost both key hooker Matt Faessler through injury and lock Jeremy Williams, who was replaced on the morning of the match by Lukhan Salakaia-Loto.

Yet with the frozen conditions having been replaced by blue skies on a perfect day for rugby, the Wallabies began confidently, making much of the running for the first quarter-of-an-hour with Noah Lolesio's 12th minute penalty their early reward.

But the Scots soon began to find their rhythm and the Australians proved ill-disciplined enough to give up 10 more metres for backchat after Tom Wright had already given away a penalty.

The visitors were lucky that Russell's penalty struck the upright.

But the Scots' first try was a shocker for the Wallabies to give away, the barnstorming Tuipulotu latching on to a long line-out throw to barge between flimsy challenges from Andrew Kellaway and Len Ikitau to touch down.

It was an emotional moment for the impressive No.12, whose gran Jaqueline was in the stands, having flown from Melbourne to watch him back in her birthland.

Shifting the shape of Scotland's increasingly potent-looking attacks, Tuipulotu was then sent crashing by a big shoulder hit from Suaalii, which he seemed to take exception to as the pair had a brief contretemps afterwards.

More alarmingly, Suaalii had to come straight off, holding his wrist as the Scots, deservedly, went in 7-3 ahead.

Russell and Lolesio exchanged early penalties after the break, and the crowd were incensed in the 50th minute when Wright stood his ground in defence, taking out halfback Ben White who was making a break.

Irish ref Chris Busby ruled it was no penalty and no card, and as if enraged by the perceived injustice, the Scots came ploughing forward, attacking towards both corner before the deadly van der Merwe ploughed over in the left corner for his 30th try.

The wheels began to come off as Bayliss ploughed over in the corner, taking three players with him, before Russell, starting to run the show with his inimitable brilliance, went over for the fourth.

Only a breakaway effort with Tate McDermott booting the ball forward brought a late smile, with Potter, making his debut in the city where his iconic fictional namesake was created, managing, after rolling over and juggling the ball a couple of times, to touch down.

There was, though, huge deflation after the first two legs of the tour had proved so exhilarating for the Aussies that leg three should prove so anti-climactic, with the Ireland match still to come in Dublin next Saturday. (AEDT)