The Junior Wallabies defeated reigning champions New Zealand 24-0 to claim their first Oceania Rugby U20 Championship on home soil in the Gold Coast on Saturday.

In a result that will have served as a warning to their Pool B rivals England, Ireland and Italy at the upcoming World Rugby U20 Championship 2019, Australia were rock solid in defence and clinically took any chances that came their way.

With both teams coming into the final undefeated, the four-time-defending champions New Zealand were tipped to be the favourites following big wins over Fiji and Japan, but the Junior Wallabies had other plans as their brilliant display of tenacious rugby kept the New Zealanders scoreless for the whole game.

In the other match on Saturday, Fiji defeated Junior Japan 59-37 to secure their only win of the tournament. 

New Zealand 0-24 Australia

Inspirational fly-half Will Harrison contributed 14 points with the boot and Triston Reilly and centre Noah Lolesio both crossed for tries but the Junior Wallabies' victory was built on uncompromising defence as New Zealand suffered only their second defeat in the five-year history of the Oceania Rugby U2O Championship.

While Harrison kicked four first-half penalties his opposite number, Fergus Burke, missed with both of his attempts at goal and the home side went into the break 12-0 up despite finishing the half down to 14 men following a yellow card to number eight Will Harris.

Australia survived the 10-minute period with their line intact and then scored the first try of the match in the 64th minute through winger Reilly. Harrison was unable to tag on the extras, his only miss of the night, but made no mistake with the conversion after Lolesio crossed for their second try with nine minutes left to play.

Elated Junior Wallabies captain Fraser McReight said that the experience of beating New Zealand in the final was a momentous one for the team.

“To do it (win) on home soil in front of family and friends for the first time in this tournament is awesome, and I’m just lost for words,” McReight said.

“It’s just been an awesome effort from the boys to keep a New Zealand side for a full eighty with a yellow card. I think it just goes to show the amount of effort we’ve put into this year and it’s a huge win and this is so good.” he added.

McReight said that the team has taken a lot of confidence out of this win going into the World Rugby Under 20 Championship later this year.

New Zealand are six-time winners of age grade international rugby's elite competition, while Australia are yet to better their runners-up finish of some nine years ago.

“I don’t think an Under 20s side has ever done that (win against New Zealand) in a very long time and we can take confidence in that, and that’s so unreal and I can’t wait for the future, and I can’t wait to win that Junior Rugby World Cup," McReight said.

Japan 39-57 Fiji

Japan number eight Takamasa Maruo scored a first-half hat-trick but still ended up on the losing side as Fiji signed off with a morale-boosting win ahead of their return to the World Rugby U20 Championship.

Maruo added a fourth try late on to cap a fine individual display but by then the match had got away from his side with Fiji running in nine tries in a riotous match that saw the lead change hands five times in the first 50 minutes.

Fiji piled on the points though in the final half an hour and will take great encouragement from their performances at the Oceania Rugby U20 Championship having pushed New Zealand and Australia hard for long periods in their earlier matches.

Fiji held a slender 28-27 lead at the interval thanks to a brace of tries from blindside flanker Vilive Miramira, scrum-half Josh Akariva Isaiah Vuta and centre Ilaisa Droasese were converted by fly-half Simione Turaga Kuruvoli.

Tight-head Sho Maeda had opened the scoring in the seventh minute for Japan who were thankful to Maruo and seven points from the boot of Rintaro Maruyama for the remainder of their first-half points.

Halatoa Vailea's penalty at the start of the second period temporarily gave Japan the lead again but Fiji then took the match by the scruff of the neck and scored three tries in the space of six scintillating minutes through their electric back three of wingers Osea Natoga and Kaminieli Rasaku and full-back Ratu Waqaninavatu.

Natoga got another on 70 minutes to make the score 52-30 to the Fijians before Maruo weighed in with his fourth try. Replacement front-rower Lino Vasuinadi added Fiji's ninth try in the 77th minute.