SYDNEY (AP) — Australia swept the men's and women's titles at the Sydney Rugby Sevens on Sunday, becoming the first nation to win both trophies in one tournament in the World Rugby Sevens Series.

The Australian women beat New Zealand 31-0 in their final to become the first women's team to win a home tournament in the World Series and the men beat defending World Series champions South Africa 29-0 to win a tournament on Australian soil for the first time in 16 years.

Both Australian teams finished the three-day tournament unbeaten and the Australian women became the first team, men's or women's, to complete a World Series tournament without conceding a point.

The Australian teams entered both finals as underdogs but swept aside their opponents to emphatically win their respective titles. The women ended a run of five-straight losses to New Zealand stretching back to the 2016 Olympic final in Rio de Janiero, when they beat the Kiwis to win the first-ever gold medal in women's sevens.

The Australian men were also underdogs in their final after South Africa swept its pool matches then beat Kenya 17-0 in the quarterfinals and the United States 35-7 in the semifinals.

Australia was also unbeaten in pool play and substantially improved its title chances when it beat New Zealand 24-12 in the quarterfinals. Another tournament favorite, Fiji, also bowed out in the quarterfinals, losing 24-7 to the United States.

Australia beat Argentina 28-0 in the semifinals, heading into the final with its confidence high.

Captain Lewis Holland scored the opening try of the final, then James Stannard scored to give the home side a 14-0 lead at the break. James Porch scored early in the second half and a double by Ben O'Donnell clinched a convincing victory.

"This is the goal we set out to achieve this year," Holland said. "This is the first one and the boys backed up from game one to game six.

"We developed and we grew. It wasn't pretty at the start but it doesn't matter how you start, it's how you finish and I think putting a big score like that over South Africa shows that we're a side which, when we get a start, is pretty unstoppable."

The Australian women, Olympic champions, won their tournament as convincingly as the men.

Australia beat Spain 29-0, Papua New Guinea 50-0 and France 43-0 in pool matches. It then beat Spain, again, 29-0 in the quarterfinals and Russia 31-0 in the semis before its emphatic win over New Zealand in Sunday's final.

Australia's rugged defense, the feature of its performance throughout the tournament, set the tone for the final. It jarred the New Zealanders in tackles, loosening passes, and made it impossible for the defending world champions to play their usual fluent style.

Australia, in contrast, pounced on every loose ball and turned half chances into tries.

Shannon Parry opened the scoring when Australia's defense forced a turnover five meters from the New Zealand line. Charlotte Caslick then darted from a ruck for her eighth try of the tournament and Australia took a 10-0 lead to halftime.

An attempted New Zealand rally was quickly thwarted in the second half. Ellia Green linked with Emilee Cherry on a break that brought Australia's third try and Evania Pelite crossed to make it 24-0 three minutes from fulltime.

More defensive pressure led to another Kiwi turnover and Emma Sykes clinched the win with a try under the posts.

"It was a tough battle out there but I'm proud of us," Parry said."We know off the back of a good defense we're going to win tournaments.

"It's a great way to start 2018 and we're looking forward to the Commonwealth Games and then the World Cup in San Francisco."