Camille Grassineau, of France, tackles Niall Williams, of New Zealand, on Day One of the Emirates Dubai Rugby Sevens World Series © Getty Images

Favourites New Zealand started from where they left with some explosive rugby on the opening day of the Emirates Airline Dubai Rugby Sevens.

The first round of the HSBC World Rugby Women's Sevens saw the Black Ferns quickly into their stride as the defending champions hardly broke a sweat.

Allan Bunting's side cruised into the last eight through Pool A and now face the United States.

New Zealand, who won all the rounds barring Sydney last season, began by thrashing South Africa 40-0 and followed it up with routine wins against France, 28-7,  and the US 45-14, at The Sevens Stadium.

Portia Woodman, Michaela Blyde, Gayle Broughton,  Kayla McAlister, Stacey Waaka and Theresa Fitzpatrick all scored tries against South Africa, while Tyla Nathan-Wong successfully kicked four conversions. 

Katarina Whata-Simpkins added another conversion.

Against the US, Blyde took just 40 seconds to put New Zealand on the road to victory and it was plain-sailing from thereon-in with Woodman scoring two tries.

Broughton, captain Sarah Goss, Ruby Tui and McAlister all scored further tries, while Tyla Nathan-Wong kicked four conversions to finish with 12 conversions in total.

Chane Stadler, of South Africa, is tackled by Ryan Carlyle, of United States, on Day One of the Emirates Dubai Rugby Sevens ©Getty Images
Chane Stadler, of South Africa, is tackled by Ryan Carlyle, of United States, on Day One of the Emirates Dubai Rugby Sevens ©Getty Images

Earlier, the tournament got off to an exciting start with Ireland seeing off Fiji 20-12 in Pool C.

Stacey Flood, Amee Leigh Murphy Crowe, Ashleigh Baxter and Katie Fitzhenry scored tries for Ireland, while Tima Ravisa scored two tries in reply and Lavena Cavuru kicked a conversion.

The Pool B opener was a thriller with Russia rallying to pinch a 17-15 over England, for whom Claire Allan was making her first appearance as captain.

Australia beat beat Japan 27-0, Russia 31-12 and England 22-7 but England will have the opportunity to avenge that loss when they meet again in the quarter-finals on Friday having seen off Japan 26-14.

Also in the last eight Russia will face Spain having also thrashed Japan 36-0 and lost to Australia 31-12.

Spain lost 19-0 to Canada in Pool C but recovered to beat Fiji 19-5 and Ireland 17-7.

The other quarter-final will see Canada take on France.

The Canadians made it three wins out of three by beating Ireland 31-0 and Fiji 31-14, whilst France pipped USA 19-17 but went on to beat South Africa 29-5.

Ireland inched past Fiji 20-12.