Richie Gray seizes on the loose ball as Australia prop Scott Sio stubs it out of the side of a ruck with his big toe.

Sean Maitland likes the look of the open field and has a dart. Big hit comes in from Sio and the ball spills forward.

Scotland used their advantage. Scrum down gold.

A bit of a bone-headed penalty given away by Scotland.

It was Alasdair Dickinson who ran around the wrong side of the ruck and tangled with Will Genia to give away the first penalty.

Image source, PA

Craig Joubert is on whistle duty. Finn Russell bangs a high, hanging drop-out and flanker Scott Fardy claims for the Wallabies.

Image source, Reuters

Princess Anne adds her voice to the slow, proud menace of Flower of Scotland.

Australia bounce into the perkier Advance Australia Fair full of the confidence that coming through Pool A with a 100% record will give you.

Image source, Getty Images

Image source, Reuters

Some big strings and burst of pyro to welcome the two sides to the Twickenham pitch.

The atmopshere is not the lid-on Cardiff cauldrom, more ancient amphitheatre.

Anthem time.

Image source, AP

Australia coach Michael Cheika, speaking to ITV Sport: "It's essential we improve from the Wales match and go to another level today. This is going down to the wire, this match."

Image source, Getty Images

Scotland coach Vern Cotter seems to unplug 80% of his brain for the pre-match media chit-chat. Very sensible.

Speaking of Fraser Brown and Tim Swinson's relegation to the bench: "These guys are proud competitors, but they understand what is best for the team. There are no egos.

"It is just a matter of getting hold of the ball and varying our game to keep us unpredictable."

Monotone and motionless through out his ITV interview.

  Ouch....  (The Wooden Spoon traditionally goes to the bottom team in the Six Nations, in case you're wondering...) 

And in case you were wondering what Harry Potter author JK was replying too...

Matt Dawson
2003 World Cup winner on BBC Radio 5 live

Image source, AP

"Losing David Pocock is significant for Australia. He and Michael Hooper are such a good combination. When Hooper makes a tackle, Pocock steals it. When Pocock makes a tackle, Hooper steals it. They win so many turnovers that way."

Gavin Hastings
Former Scotland full-back on BBC Radio 5 live

Image source, Reuters

"I just hope that Scotland really take a few risks and believe they can cause Australia some problems. They've scored some fantastic tries during this World Cup, and I hope they can score a few more."

Image source, Getty Images

Israel Folau's injury allows Kurtley Beale to come into the Australia starting XV.

The 26-year-old has had his off-the-field issues, but there is one heck of a player in there - an electric runner, an almost extra-sensory feeling for space and a supercomputer of a rugby brain.

He was a much-heralded talent as a schoolboy, referred to as "Mozart in cleats" by one national newspaper.

You can see why in this highlights package from his school days., external

Tom Fordyce
Chief sports writer at Twickenham

"Clouding over at Twickenham, and Scotland left as the northern hemisphere's sole ray of sunshine in this World Cup. Even the kilted in the towering stands are hopeful rather than expectant against this hugely impressive Wallabies' team, but with Harry Potter author JK Rowling here to cheer her nation on, might there just be a little magic in the air?"

Image source, BBC Sport

• This will be the second World Cup meeting between these sides having met at the same stage in 2003, a game which Australia won 33-16 and in which today's centurion Matt Giteau featured as a replacement fly-half.
• Australia have won 17 of their last 19 Test matches against Scotland, however those two defeats have come in their last three meetings (2012 and 2009). 

Image source, Getty Images

For our younger readers, Callum has updated Ally's Tartan Army - the official Scotland World Cup song of 1978.

The northern hemisphere has always had at least one representative in the semi-finals in each of the previous seven World Cups. 

When France made the 1999 semi-finals was the only time no home nation made the last four.  

But every other staging has seen two northern hemisphere sides make the last four.

Image source, PA

Scotland have gone for two breakdown bloodhounds with Blair Cowan at six and John Hardie at seven.

Can they keep the possession supply lines open for their dangerous backline runners?

BBC's Tom English looks at where the game might be won and lost today, and wonderswhether the Cowan-Hardie axis might be a good idea that Vern Cotter has turned to too late.