Wales can start dreaming of reaching their first Rugby World Cup final if they beat Australia on Sunday, according to Sam Warburton.

Two-time semi-finalists Wales started their 2019 campaign with a comprehensive 43-14 triumph over Georgia in Pool D but a stiffer test lies in wait in Tokyo on Sunday when they face Australia.

Warren Gatland's side ended a 13-match winless run against the Wallabies last year with a 9-6 success and Warburton sees the latest encounter as critical to Wales' hopes of going further than they ever have before in the tournament, with the winners of Pool D likely avoiding reigning champions New Zealand or England until the final.

"It's the most open World Cup we've ever had," Warburton, who won 74 caps for Wales, told Omnisport.

"They [Australia] are clear front-runners. Australia will be really competitive and if Wales can win against Australia and get out of the group first, I think it will give them the confidence and a slightly easier route - they're probably going to dodge England and New Zealand to the final.

"I think [for] Wales then it will be a really good springboard to get to a World Cup final.

"If they lose then they are going to have to do it the tough way and beat England and beat New Zealand and probably someone like South Africa in the final.

"That Australia game is massive, both teams realise how big that's going to be. If Wales can win that then I expect them to do good things."

Australia had a rotten 2018, with that defeat against Wales one of nine Tests they lost in the year.

They have fared better in 2019, though, and Warburton took notice of their impressive 47-26 victory over New Zealand in August.

"They've got the ability to beat New Zealand without David Pocock," the former British and Irish Lions captain added.

"If you can add David Pocock - and I know they've played them since and lost pretty badly - but it shows that that's in there. Like, it's there somewhere, they've still got it.

"So with Pocock fully fit added to that team, it wouldn't surprise me if they made last four."

Open Side by Sam Warburton (HarperCollins) is out now.