Rugby World Cup Sevens: New Zealand go back-to-back to win World Cup, Australia claim Bronze

New Zealand have claimed a historic back-to-back Rugby World Cup Sevens title, and 26 straight wins, after they hammered France 29-0 in the gold medal final at AT&T Park in San Francisco on Sunday.

New Zealand were hardly challenged on their way to the 2018 title, making easy work of Mexico (57-0), Ireland (45-0) before they out lasted USA (26-21) in the semifinals.

The Black Ferns' superstars were on the ball early with Michaela Blyde, Portia Woodman and Tyla Nathan-Wong all crossing the whitewash in the opening half to take a 15-0 lead into the break.

The Black Ferns were forced to work hard early in the second, with France holding strong in defence, but eventually Blyde slipped through the gaps to add her second and third tries of the final to shut France out and claim the title.

Australia put disappointment behind them to clinch the bronze medal with a 24-14 win over the United States.

Ellia Green bagged two tries and Charlotte Caslick delivered a reminder of her class in the match for third place.

Claiming a medal delivered some comfort for the Olympic champions who were stunned 17-12 by France in the semi-finals earlier on Sunday (AEST).

Supersub Green unveiled her pace twice in the second half to see off the tournament hosts, after the scores were locked 7-7 at halftime.

Playmaker Caslick set up the first of them with a cross-kick, having earlier put Cassandra Staples across with a neat inside pass.

Evania Pelite scored an 80 metre solo try in the first half, to end the tournament with six. That left her one behind US flyer Naya Tapper, who bagged both of her team's tries in the bronze match.

Spain outlasted Ireland 12-7 to claim fifth place after they stole victory in the dying seconds with a Teresa Bueso Gonez try in the corner. While Canada downed Russia 22-10 in a tough clash to finish seventh.

Earlier, England overcame disappointment to defeat Japan 31-5 and take out the Challenge Cup. After a disappointing opening game loss to Ireland, England proved too good for Mexico (59-0) and China (38-0), before they took out the Challenge cup in emphatic fashion.

Fiji dismantled China 38-0 to take out 11th place, before Brazil were too good for South Africa, claiming 13th place with a 22-0 win and Papua New Guinea took out 15th place 32-0 over Mexico in the final match of the women's competition.