The Hockeyroos know their best ever start to an Olympics will count for nothing if it is followed by a quarter-final loss to India in Tokyo on Monday.
Australia, who emerged from a scathing external review with a new coach in Katrina Powell just four months ago, beat Argentina 2-0 on Saturday to make it five wins from five pool games.
Powell's side were all but assured of top spot in Pool B at the outset of Saturday's clash, needing only to avoid a rout of unthinkable proportions.
Tensions flared after three scoreless quarters, but Savannah Fitzpatrick broke the deadlock in the 49th minute then created another goal for prolific veteran Emily Chalker.
The Hockeyroos, hunting their first Olympic medal since Powell was part of the team that won gold at Sydney 2000, quickly shifted focus to their knock-out match.
"We said going into this game we want momentum, we want to win. When you're winning, you're confident," Jane-Anne Claxton said.
"We know that this quarter-final means everything.
"It's not every day that you win five out of five at an Olympic Games but, unfortunately, this is now the business end and that won't count if we go into a quarter-final and aren't successful."
Fitzpatrick's goal came after a defensive error from Argentina, who had controversially brought the game to a halt moments earlier by calling for a dubious video review as the opposition attacked.
"Karma," Claxton quipped.
"We just said it was probably more of a tactical referral because we had a breakaway and likely to score. That's on each team, they can use their referrals how they wish."
Fitzpatrick, asked about Argentina's video review, noted she was "pretty frustrated" and "everything happens for a reason".
"It was really good to get the reward for our hard pressing," she said.
"The job's not done and our most important game is 100 per cent the next one."
Chalker, among the Australians gunning for redemption after being part of the squad that suffered a quarter-final loss at Rio 2016, scored her fifth goal of the tournament with 95 seconds remaining on the clock.
Reigning Pro League goalkeeper of the year Rachael Lynch, who successfully appealed her shock non-selection by the squad's former hierarchy, has conceded just one goal in Tokyo.
Powell, who won Olympic gold in both 1996 and 2000, was appointed coach in March after Paul Gaudoin's resignation.
Former high-performance director Toni Cumpston also resigned amid the fallout of an external review that made 29 recommendations in response to a "dysfunctional" culture.
The review was sparked by claims of body-shaming, bullying and other issues.
Australian Associated Press