Australia's women have gone through day one undefeated in Hamilton but it was a mixed bag for the men.
The Aussie women breezed past Brazil and Russia, with returning star Emilee Cherry playing a key role in both matches, setting up a pool decider against the USA on Sunday morning.
Australia's men won their first clash against Argentina easily but a classy Fiji side proved a road block in a 19-12 loss.
With the new format in Hamilton not including Cup quarter-finals, the Aussies will not know their finals fate until after the final pool round tomorrow morning.
5:57pm - MEN - AUSTRALIA vs FIJI
Australia's semi-final hopes are hanging by a thread after a 19-12loss to Fiji in their second pool match on Saturday.
With no Cup quarter-finals in Hamilton, only men's pool winners will progress to the cup finals.
Fiji is sitting at the top of the pool after day one as the only undefeated team with one round of matches to go.
For any hope of progressing, Australia would have to beat Samoa by a huge margin and hope that Argentina can spring an upset on the Fijians, also by a big margin.
If that were to happen, three teams would be 2-1 in their pool and the semi-finalist would come from the team with the best for and against.
Australia threatened in attack early in their second match. but their defence was tested by the Fijians as the first half ticked along.
Lachie Anderson was desperate in defence, rushing out of the line to stop the Fiji attack.
An attempt at an out the back pass from Nick Malouf took a disastrous turn, going straight into the Fijian defender, with Asaeli Ratavuaka finishing.
Some uncharacteristic errors from Fiji stopped them from stretching that lead but they were still in control at the break.
Fiji turned defence into attack early in the second half, going from their own in-goal to score in the ninth minute.
Dylan Pietsch reignited Australian hopes with three minutes to go, snapping up a Ben O'Donnell offload to score.
Fiji's attack, though, continued to show its class and some hot potato offloading resulted in another Fijian try.
A yellow card for Fiji gave Australia a late opportunity to mount attack but the clock was not their friend.
Ben o'Donnell clinched a consolation try with the last play but it wasn't enough to clinch a win.
The Australian men face Samoa at 10:35am AEDT on Sunday.
Tries: Pietsch, O'Donnell
Tries: Ratuvuka, Tuimaba, Cakaubalavu
Cons: Nacuqu 2
2:32pm - WOMEN - AUSTRALIA vs RUSSIA
Australia face a pool-topping shootout against the USA on Sunday morning after a 40-12 pool win over Russia.
The Aussies have won both of their two pool matches on day one but with a new cut-throat format in place in Hamilton, that is no guarantee that they will progress further.
With men’s and women’s competitions being held over just two days, there are no quarter-finals in the New Zealand World Series leg and only pool winners are guaranteed to qualify for the finals.
Australia have put themselves in the box seat to do that but a tough USA outfit awaits in their final pool game on Sunday morning.
Ellia Green burst through the Russian defensive line for her first in the second minute.
Russia looked dangerous two minutes later, breaking a Sharni Williams tackle before being brought down by a desperate Emilee Cherry tackle.
An offside penalty gave the Russians a second chance to go for the line and they did exactly that, through XXX.
Cassie Staples gave the Aussies the lead again, collecting an Emma Tonegato offload and streaking down the right edge to score.
Staples had her double just before the break and the Aussies took a three-point lead into half-time.
Alicia Lucas slipped through a gap to score first in the second half and Emilee Cherry scored an opportunistic five-pointer after picking off a Russian in-field kick.
Rookie Madison Ashby was tenacious in defence, standing up against some more experienced opponents and fellow teen Sariah Paki had the match-sealer in the 12th minute.
Russia had a consolation score in the final seconds but by then the result was well and truly decided.
Australia’s women will take on the USA at 7:51am AEDT on Sunday.
Tries: Staples 2, Green, Lucas, Cherry
Cons: Williams 2, Williams, Sykes
11:44am - MEN - AUSTRALIA vs ARGENTINA
The Aussie men have made an emphatic start to their Hamilton campaign with a 38-7 win over Argentina.
Maurice Longbottom, who was rested for last year's Cape Town tournament, made an immediate impact with two tries in the match while fellow Hamilton inclusion Ben O'Donnell was hugely influential.
Maurice Longbottom made an immediate impact on the Hamilton stage, blitzing the Argentinian defence to score a super solo try in the opening minute.
Argenitna hit back in the fourth minute with Matias Osadzcuk pouncing on a grubber just in the nick of time to level things up.
Ben O'Donnell opened the door for Australia's second, stepping the Argentinian defence and streaking down the edge before offloading to Henry Hutchison for the score.
Lachie Anderson made it three Australian tries just before half-time after a sneaky Maurice Longbottom grubber floated cross-field into Anderson's line.
Lewis Holland became the most prolific Australian men's Sevens try scorer with the first score of the second half, his 100th career score.
Longbottom nabbed his second midway through the second half to stretch the lead out to 26 points and another perfectly-timed step and offload from the speedster sparked an attacking chain that ended in a Josh Turner try.
With the abolition of quarter-finals in Hamilton this year, Australia must top their pool to stay in Cup contention and a win keeps them on track to do that.
They play Fiji in their second pool game at 5:35pm AEDT.
Tries: Longbottom 2, Hutchison, Anderson, Holland, Turner
Cons: Holland 2, Longbottom 2
8:57am - WOMEN - AUSTRALIA vs BRAZIL
A first-half Emilee Chery double has helped Australia to a 24-14 win over Brazil.
The veteran made a triumphant return t othe field with two tries in two minutes to steady the ship for the Aussies after a slow start.
Cherry hasn't played in more than 18 months after battles with injury and then the birth of her daughter, but she didn't miss a bea in her comeback.
The Australians' plan was to ease the superstar back into action somewhat but she was in the thick of things from the get go.
Brazil's tenacious defence forced some early errors from the Aussies, and a length of the field
Thalia Costa collected an offload deep in Brazil's own territory and went coast-to-coast to score the opener.
Emma Tonegato looked for an immediate reply but was taken down in midfield as Australia looked to build pressure.
It was Cherry who found the line first, with a signature finish, slipping through a gap in the Brazilian defence.
Cherry had her second just two minutes later to give Australia the lead, and her defensive pressure also forced Brazilian speedster Costa into touch as she appeared on track for a second.
Ellia Green put in a gladiatorial effort to see off Costa in the early stages of the second half and a quick switch opened up a gap for Emma Sykes to score.
Green used her pace to nab the Aussies' next, though Costa was hot on her heels
Australia spent the final minute a player down after a yellow card to Rhiannon Byers for a neck roll.
The Aussies opted to go for a final try after a late penalty but the Brazilians had the final say with a last-gasp score to Rafaela Zanellato.
Australia plays Russia in the next game at 2:14pm AEDT while the men face Argentina at 11:25am
Tries: Cherry 2, Sykes, Green
Cons: Sykes 2
Tries: Costa, Zanellato
Cons: Kochhann 2
Women's Sevens squad
1. Rhiannon Byers, University of New England, NSW, 4 caps
2. Sharni Williams (c), University of Canberra, ACT, 32 caps
3. Sariah Paki, University of Technology Sydney, NSW, 9 caps
4. Cassandra Staples, University of Queensland, NSW, 10 caps
5 . Emma Tonegato, University of Wester Australia, NSW, 28 caps
6. Demi Hayes, Griffith University, Queensland, 10 caps
7. Dominique Du Toit, University of Western Australia, QLD,
8. Madison Ashby, University of Technology Sydney, NSW, 3 caps
9. Emma Sykes, University of Queensland, QLD, 5 caps
10. Alicia Lucas, University of New England, NSW, 32 caps
11. Emilee Cherry, University of Queensland, QLD,
12. Ellia Green, University of Melbourne, Victoria, 28 caps
13. Faith Nathan, University of Technology Sydney, NSW, 2 caps
1.Nick Malouf (c), University of Queensland, 36 caps
2. Joe Pincus, Easts (Sydney), 8 caps
3. Lachlan Anderson (vc), Eastwood, 23 caps
4. Jeral Skelton, Brothers, 16 caps
5. Jesse Parahi, Norths (Sydney), 46 caps
6. Dylan Pietsch, Randwick, 14 caps
7. Maurice Longbottom, Lloyd McDermott Rugby Development Team, 16 caps
8. Josh Turner, Manly, 2 caps
9. Lewis Holland (vc), Queanbeyan, 48 caps
10. Ben O’Donnell, Randwick, 18 caps
11. Henry Hutchison, Randwick, 27 caps
12. Lachlan Miller, Randwick, 8 caps
13th Rod Davies, 2 caps
Saturday January 25
8:36am - Australia vs Brazil
2:14pm - Australia vs Russia
Sunday January 26
7:51am - Australia vs USA
Saturday January 25
11:25am - Australia vs Argentina
5:35pm - Australia vs Fiji
Sunday January 26
10:35am - Australia vs Samoa