Alice Arnott scored for the second time in as many Olympic Games as the Hockeyroos shut out the United States to book an early quarter-final berth.
Australia's 3-0 win followed a dominant 4-0 defeat of Great Britain and a scrappy 2-1 result against South Africa to begin their Paris campaign.
Their 3-0 start was enough to book a spot in the final eight with two pool games still to play.
Striker Arnott missed the opener with injury but has made an impact on return with her craftiness around the circle, scrambling a goal on Olympic debut against Britain.
On Wednesday she was clinical, a great first touch allowing plenty of time to slap a shot into the roof of the net for a 2-0 lead.
Renee Taylor had opened Australia's account after just three minutes, drilling an effort into the left sideboard from open play.
And Maddison Brooks finished the job, a clean strike in traffic beating goalkeeper Kelsey Bing to her left after a neat one-two with Arnott on the edge of the circle.
A travelling injury reserve, Brooks made the most of her call-up after co-captain Jane Claxton was withdrawn with a calf injury.
Tatum Stewart (knee) was also pulled from the active squad, replaced by Hattie Shand.
Like with Arnott, both players are able to return to play once fit at their injury replacements' expense.
Katrina Powell's side is chasing its first medal since the team claimed a third gold in four Games at Sydney 2000.
They sit on top of their pool thanks to goal difference, ahead of games with the unbeaten Argentina on Thursday and Spain (1-1) on Saturday.
The Netherlands are hot favourites after a dominant Pro League season and will likely play Belgium on Friday to decide who tops the other pool.
