Australia's rugby sevens women have suffered yet another final let-down against their great New Zealand rivals, missing out on the marquee Hong Kong Sevens crown with a 19-14 defeat.

In the first of three tournaments which make up this year's world championships, the New Zealanders moved into pole position by beating their trans-Tasman rivals in a fifth final of the year following previous wins in Singapore, Perth, Vancouver and New York.

The two sides have become completely dominant in the women's world series as they played a 10th consecutive final at Hong Kong's Kai Tak Park - but it's becoming close to a monopoly as Risi Pouri-Lane's New Zealanders have won nine of those.

Australia were hoping to emulate their lone triumph of the season over New Zealand, in the Cape Town final in December, after they had beaten France 26-5 earlier in Sunday's semi-final, courtesy of two tries each for Maddison Levi and Tia Hinds.

But they were undone at the start in the showdown as Mahina Paul scored a brilliant solo effort from distance on her 25th birthday to launch the Kiwis' march.

Jorja Miller then shook off Madison Levi in a duel between the two best players in the sevens game to put them 14-0 up, before captain Bella Nasser's neat fake step-and-dart from distance helped the Aussies reduce the deficit to 14-7 at halftime.

But Australia's hopes were effectively dashed at the start of the second period when Teagan Levi took out Miller in the air when challenging for the restart kick and got two minutes in the bin, during which Kelsey Teneti scored the Kiwis' third.

There was a late moment of magic from Maddison Levi, bursting past two markers down the left flank to score her seventh try of the weekend, but it was too little too late as New Zealand celebrated their fourth-straight Hong Kong triumph.

In the men's event, South Africa's Blitzboks broke their Hong Kong hoodoo in the 50th anniversary event, winning the title for the first time by defeating Argentina 35-7 in the final.

Four times, the South Africans had previously lost in the Hong Kong final but they were dominant from the moment Tristan Leyds punted from inside his 22, chased down the ball, collected and raced between the posts.

Meanwhile, Australia's men had to settle for a disappointing sixth place, losing their fifth-place play-off clash to Fiji 26-10.

The second leg of the world championship finals will be staged in Valladolid, Spain, in late May, before the title is decided in Bordeaux, France, the following week in June.