The All Blacks star is expected to remain on the sidelines for 6-9 months.

It is a cruel blow to Williams who made a sterling rise in the sport after coverting from the 15-man game in January this year.

The injury robs the All Blacks of their most experienced centre for 2016 an beyond.

“It’s devastating for Sonny to lose him so early in the tournament, and Joe Webber, both influential players as well,” New Zealand coach Gordon Tietjens told reporters at Deodoro Stadium in Rio.

“He loves the game of sevens and I’ll be surprised if he doesn’t play sevens again.

“Sonny Bill’s a great professional, he’s very infectious, he certainly helps the younger players and has a great work ethic.

“It’s such a shame because he’s got to understand the game of sevens so well.

“He’s absolutely shattered.”

Meanwhile, Australia was annihilated 31-14 by France in their pool B opener before recovering to down Spain 26-12 in game two.

The Aussies now face unbeaten South Africa in their final group game.

And they will have to carry on without star player Lewis Holland who was ruled out of the tournament with a hamstring injury.

He has been replaced by Tom Kingston.

“He is a class act in the 10 position but if he is not right he is not right,” Australia coach Andy Friend told reporters.

“Other teams are losing players, you have to work through that.”