Australia and New Zealand have declared their women's sevens rivalry the most competitive in world rugby ahead of the weekend's Sydney series.

New Zealand reclaimed top spot in the world series with a win last weekend at home, as Australia failed to progress to a tournament final for the first time this season.

Prior to that the teams had featured in the past four tournament finals dating back to last season, with honours split at two apiece.

On numbers alone the teams have every right to make the case for their rivalry being the most competitive.

Unlike the Bledisloe Cup in the 15-a-side game, which New Zealand's men have held since 2003, honours have been more evenly split between the two women's sevens sides.

New Zealand have won six women's world series to Australia's three, while the head-to-head record over the past three years stands at 3-3.

"I think it is (the most competitive)," Australia captain Demi Hayes said when asked if the rivalry was the most competitive in world rugby.

"We always come up against them in a semi-final or final ... It always is a good rivalry.

"We love playing the best and that's all we want.

"To be the best you have to play the best. If we're beating them, that's the best we can do."

Australia must win at Allianz Stadium and have New Zealand fall out in the semi-finals or earlier in order to regain top spot in the world series.

The final three events of the season will then follow in Vancouver, Hong Kong and Toulouse in March and May.

New Zealand had dominated the sevens series in its early years before Australia's improvement in the format since 2016 made them a genuine challenger.

New Zealand captain Sarah Hirini said that had lifted her side again and she agreed with Hayes about the rivalry being one of the most competitive in world rugby.

"It's amazing and it has been like this right from when I debuted in 2012," Hirini said.

"It's pretty amazing for both teams to be very successful and competitive every years.

"It's obviously shown in the World Series results, it's either us or them winning it at the end of the year.

"When I look at it, we want to beat them. But they've helped drive the game forward, they have helped change things in women's Sevens.

"So if we can both continue to keep going competitively it makes it a great spectacle and drives the game forward."