Maddison Levi has powered Australia to victory, scoring four as they comfortably defeated Spain 46-0.
Levi crossed for a second-half hat-trick as the defending World Series champions defied the wet conditions to deliver a confidence-boosting win.
She was supported by fellow strike partner Faith Nathan, who brought up 50 tries on the world circuit as she scored a double in the wet conditions.
After a sloppy showing against Brazil, the win pleased coach Tim Walsh despite some defensive lapses in the first half.
"I think defensively it was most pleasing," Walsh said.
"They didn't start well...they were going a bit high in defence but they finished well.
"We didn't expect the rain and how to win restarts or how to play strategically I thought they adapted pretty quickly which was nice.
"A nice way to finish day one."
Levi stole the show, with the highlight being a solo 70-metre effort before the half-time break that saw the 20-year-old pick up the loose ball and run around several Spain defenders to score under the posts.
Making it extra special was how she combined with sister Teagan, who set up her second with a great hit and pilfer before throwing the final pass for her third to delight the sea of friends and family sporting t-shirts with their faces.
"We always like to link up on the field no matter where we are but to have the people supporting us from grassroots (to also) now play with someone who I've played with my whole journey of Rugby, it's pretty exciting to put on a show like that," Levi said.
They will resume action in the afternoon against Ireland, with top spot in the Pool on the line.
"Winning two games today is pretty good but doesn't mean the work is over. We have a massive game tomorrow against Ireland and moving into the finals, we want to keep improving every game and keep working as we do," Levi added.
"We don't need to change much but coming out (the) first game, we were a bit excited and nerves were a bit all over the place. We're happy to play but it can be a bit draining on your body so hopefully, we've worked into the combinations and proved we can play good footy when we want to."
Australia 46 (TRIES: M.Levi 4, Nathan 2, Ashby, Caslick; CONS: Williams, du Toit, Hinds) defeated Spain 0