Legendary Australia back-row George Smith has backed the Wallabies and also Fiji to make it out of Pool A at the expense of England and Wales.
The 111-cap flanker will be a keen observer when the 'group of death' kicks-off with host nation England taking on Fiji at Twickenham on September 18.
And he expects a surprise pool finish for the islanders, who he believes cannot be underestimated after their recent Pacific Nations Cup final win over Samoa.
"It is going to be extremely competitive in, as they say, the pool of death," Smith told walesonline.co.uk ahead of the mouth-watering World Cup tournament.
"The English and Welsh, from what I'm led to believe, have been training extremely well while Australia have won the Rugby Championship.
"But I think Fiji are going to go through with Australia.
"I played against a number of their players in the French Top 14 last season while I was with Lyon and they are very good."
Fiji boast such quality players as Nemani Nadolo, Metuisela Talebula, Asaeli Tikoirotuma, Leone Nakarawa and Nikola Matawalu to name but a few and Smith has warned Australia and company not to take them lightly or risk being punished.
"Anybody who underestimates Fiji will be in trouble," he said.
"I have known their coach John McKee for a number of years and have been impressed in how he brings players together and manages them.
"With Fiji that is the key because when they are happy they perform. John is very good at that, as you can see from the results because they have performed well and improved in the last couple of years."
While backing Fiji for progression out of the pool, Smith believes Australia will be the team holding the Webb Ellis trophy aloft on October 31.
"Australia have a strong nucleus of players, different combinations at number 9 and 10 while back-row forwards David Pocock and Michael Hooper can change the momentum of a match in the blink of an eye," he added.
"The Wallaby lineout has always been competitive while the scrum performed well in the Rugby Championship, so it's extremely encouraging for the World Cup.
"I hope us winning both previous finals on British soil is an omen. Players will be aware of what's happened in the past and take motivation from that."