Held goalless by Alen Stajcic's Malditas despite dominating the first half in Mumbai, Gustavsson revealed after the match Kerr had played a key role in the halftime discussions which resulted in a turnaround in fortune in the second 45 minutes.

The 28-year-old also broke the deadlock six minutes after the interval to relief any frustration that had built up before an own goal and further strikes from Emily van Egmond and Mary Fowler wrapped up the win.

Kerr's headed goal in the 51st minute is already her sixth of the tournament after a five-goal display against Indonesia and Gustavsson said he loved coaching Australia's all-time leading goalscorer in international football.

"I've said that from day one that I'm really appreciative that I can be a small part of Sam's amazing career," the Swede said.

"She's an amazing player, but maybe more so an amazing captain and an amazing person.

"It's a privilege to work with her every day.

"Not to reveal what she said in half-time but it's not just me talking in halftime, it's her as a captain as well, and she's leading this team in such an impressive way that I'm just thankful to get the chance to work with her."

Australia's win means they have sealed a place in the last eight and can secure top spot in the group with a positive result against Thailand on Friday.

Gustavsson said while the aim is to continue his team's form against the Thais, he will also approach the match with one eye on the knockout stages.

Defenders Alanna Kennedy and Ellie Carpenter may not be risked as they are one yellow card away from a suspension while Cortnee Vine, who made her debut off the bench on Monday, and fellow up-and-comers such as Kyra Cooney-Cross, Remy Siemsen, Holly McNamara and Clare Wheeler will also be pushing for more minutes.

"We're going to treat that game the same way we've done with these two," Gustavsson said.

"We had two main targets, main goals for the group stage. One was to win the group and two was to get out of the group with as many players as possible available and peaking physically and mentally going into the playoffs.

"Now we have secured a spot in the playoffs which is good, we have almost secured the first spot ... we're going to do that in a way where we make sure we have as many players as possible available for the quarter-final but also peaking."

Australian Associated Press