The Kangaroos are world champions for the 12th time, taking down Samoa 30-10 in the Rugby League World Cup final at Old Trafford.

The men's side's victory at the home of Manchester United completed a double for Australia, with the Jillaroos even more comprehensive in their 54-4 victory over New Zealand in the women's final.

But while the Jillaroos were up against their old rivals who they know inside and out, the Kangaroos faced a team of destiny in the shape of Samoa, but there was to be no fairytale underdog story.

The Pacific Islander stars never truly threatened to cause an upset in their first World Cup final, with the Australians boasting too much firepower across the park, as fullback and captain James Tedesco won player-of-the-match honours for his two-try performance.

He also broke seven tackles and ran for a game-high 199 metres, per StatsPerform.

The Kangaroos have not been beaten at a World Cup since losing the 2008 final to New Zealand, sporting a perfect 18-0 record, including three straight finals, since then.

That experienced showed for the full 80 minutes in Manchester, although an early refereeing blunder could have changed the complexion of at least the first exchanges.

In the fourth minute, Samoa hooker Chanel Harris-Tavita attempted a 40/20 that should have been awarded, but on-field officials missed Tedesco's toe on the line as he dove to bat the ball back in-field.

From there, Australia pounced on every mistake, getting a running start from a poor Jarome Luai kick into the in-goal, with Nathan Cleary sending Latrell Mitchell over for the opening try in the 14th minute on the back of the ensuing sets of six.

Tedesco got his first almost immediately after, with winger Josh Addo-Carr breaking through the middle and finding his skipper supporting through the middle.

Harry Grant sent Liam Martin over on the half-hour, and Australia took a 14-0 lead into half-time, but there was more drama to start the second stanza.

After a Valentine Holmes knock-on, Angus Crichton picked up the loose ball, and Harris-Tavita ran in to give Crichton a few words of advice, but the Australian back rower collected him with a forearm to the head.

Harris-Tavita was knocked out of what could be his final game, and Crichton was sin-binned for 10 minutes, but Samoa could not capitalise on their numerical advantage.

In fact, the Kangaroos managed to cross with just 12 men, with Cleary sending Cameron Murray through a hole with just under half an hour left.

Samoa got on the board, much to the crowd's delight, with Brian To'o on the end of a right-side shift that featured a stunning long ball from Luai, but Australia answered right back with a slick set play for Tedesco's second.

Stephen Crichton scored a trademark intercept try heading into the final 10 minutes, but it was too late for a comeback, with Mitchell's second sealing the victory.

Jillaroos thrash New Zealand's Kiwi Ferns in dominant Rugby League World Cup final performance:

Ali Brigginshaw has been at the top of women's rugby league for longer than just about anybody else but for all the games she's played and the trophies she's won, it's doubtful that even she has had many games like this.

Brigginshaw was the best player on the field by a distance in Australia's 54-4 World Cup final demolition of New Zealand at Old Trafford, a game that served as a reminder that the Broncos playmaker is the finest player ever to lace on a boot in women's rugby league.

She's now won player of the match awards in back-to-back World Cup finals and this, surely, was her finest hour.

Brigginshaw began the tournament with some questioning if she was too old and she ended it breakdancing in confetti with the player of the match medal around her neck.

"It's been a challenging year, going in and out of form, and I'll be the first to admit that," Brigginshaw said.

"But I enjoy my footy and I feel comfortable in this jersey and when I have the support of the coaching staff and the girls, no matter what other people say, I know they believe in me.

"It helps me play the way I want to play.

"There's been a new Ali [on this tour], the girls have made me come out of my shell and as I'm getting older it's been nice to be that not-so-serious girl. I've really enjoyed myself, I don't want this feeling to end.

New Zealand came to the Theatre of Dreams with an upset on their mind, and after their narrow loss to Australia in the group stages it seemed like they had a serious chance.

But once the dust settled after Brigginshaw's opening salvo, the World Cup was all but won.

It wasn't just that Brigginshaw played a hand in each of Australia's first three tries, it was the way it all happened.

Original Story By | Jon Healy