The Black Ferns Sevens have defended their World Cup title, thrashing France 29-0.

A hat-trick to Michaela Blyde and tries to Portia Woodman and Tyla Nathan-Wong saw the Black Ferns dominate the final, and back up their 2013 success.

Blyde was the star, opening the scoring early. The diminutive speedster couldn't quite break the last line of defence, but was released, and got up again to cross the line.

Woodman's try was similar, finishing off a long string of phases following a break by Sarah Goss. She too was tackled just short of the line, but placed the ball in the tackle, regathered it, and dove over to score.

It looked like it would be 10-0 at the break, but some quick thinking from Nathan-Wong after the first half hooter saw her take a quick tap and scoot into a hole to give the Ferns a lead they wouldn't relinquish.

Blyde completed the rout in the second half, notching two more tries to claim her hat-trick, and put the cherry on top of a superb tournament for the Black Ferns.

Allan Bunting's side kept a clean sheet through yesterday's opening two knockout games, before overcoming a relentless USA side in the semifinals, coming from 14-12 down to win 26-19 in a thrilling final four match-up.

The All Blacks Sevens are also on course to defend their title after completing a dramatic comeback victory on day two in San Francisco today.

The men's team booked a spot in tomorrow's semifinals where they will meet Fiji after a 12-7 quarter-final victory over France where they earned more yellow cards than tries. Despite having three men sent from the field in the opening half, New Zealand held onto only trail 7-0 before tries to Kurt Baker and Joe Ravouvou secured the win.

They face a very strong looking Fiji side tomorrow who dispatched of Argentina 43-7 in their quarter-final. England needed an extra-time win over hosts USA to set up a semifinal clash with South Africa who thrashed Scotland 36-5.