Oita - Forwards win games and backs decide by how many points runs the old rugby adage.

And the reason it's a familiar saying is because it is so often proved to be true, as England centre Henry Slade showed by repaying his selection with the key moment of the first half.

The English backs clearly demonstrated their worth during their 40-16 win over Australia in the World Cup quarter-final at Oita on Saturday.

Both England coach Eddie Jones and Australia boss Michael Cheika, his former team-mate at Sydney club Randwick, had reshaped their backlines for this match.

Jones decided to drop fly-half George Ford to the bench and move England captain Owen Farrell from inside centre to stand-off, with Slade recalled to partner Manu Tuilagi in midfield.

Meanwhile Cheika sprung an even bigger surprise by drafting in teenager Jordan Petaia, best known as a wing, to outside centre where he was alongside powerful runner Samu Kerevi.

The 19-year-old Petaia showed some early glimpses of class with his quick feet leading to a couple of half breaks.

He was also linking well with Kerevi, creating a few nervous moments for England.

But it was the guile of Slade that helped justify Jones's decision to select the 26-year-old on the back of just 40 minutes of rugby since he suffered a left knee injury in preparation for England's first World Cup warm-up match in August.

England were already leading 7-3 when Slade, in his first start of the World Cup, intercepted a loose pass from veteran Wallaby flanker David Pocock and charged down field.

It was then that Slade's rugby brain came to the fore, showing that nous still plays a part in modern rugby which now revolves so much around speed and strength.

He could so easily have tried to sprint on or thrown a wild pass. But knowing he lacked the pace to go clear of the cover, Slade produced a superbly weighted grubber kick regathered by Jonny May for the left wing's second try in three minutes.

It was a key play as, with Farrell adding the conversion, it meant England led 14-3 in the 23rd minute.

From then on it was their match to lose and before the half was over, Slade showed his defensive skills with an important tackle on Kerevi.

Jones replaced Slade with Ford in the 61st minute as Farrell moved across to inside centre but by that stage the Exeter midfielder had more than played his part.