Australia will have the chance to claim dual titles in Perth for the first time since 2018 after the Men upset Fiji 22-7.
It was exactly six years ago that both the Men's and Women's sides hoisted titles together in Sydney, with the Women's side booking their place earlier in the day with a strong win over the USA.
"It'd mean a lot," vice-captain Maurice Longbottom said, the only player remaining from that side in 2018.
"It's a big year for us boys leading into Paris so every tournament is a tick along the way so if we can get a win here, it'd be perfect for us in our road to Paris."
The Australians were forced to fight hard for the win as the Fijians came out looking for revenge after their Cape Town defeat and troubled the Aussies early with their offload game.
John Manenti’s side showed great fight in defence to contain the Fijians and eventually cause some key turnovers.
It presented the first opportunity of the game for Australia to strike as Maurice Longbottom attracted the defence in and produced a great crash ball to captain Nick Malouf for the opening try.
However, you can only contain the Fijians for so long and they levelled the scores after a breakaway try via Joseva Talacolo.
The Australians were never going to give up and super sub Dietrich Roache once again was the spark they needed, breaking away before Nathan Lawson finished in the corner two phases later.
Their defensive pressure, particularly Nick Malouf, eventually wore down the Fijian attack and presented a rare penalty opportunity for Maurice Longbottom to extend the lead outside of a converted try.
Young gun Henry Palmer sealed the win with a try late in the game to secure their place in the decider against Argentina in a rematch of Cape Town.
"We had to put the pressure on (Fiji)," Longbottom added.
"They're an unstructured team and we like the structure so we had to set rucks, get in their offload channels and it ruins their game.
"There's a reason (Argentina) are on top. They are playing some outstanding footy and we just have to be better in the air. We've got to be physical and get up for the fight."