Forward Sam Kerr admitted she was unaware of the importance of her fourth goal which meant Australia progressed as Group C runners up.
Kerr scored all four goals in the Matildas' 4-1 win over Jamaica which meant Australia finished behind Italy, who lost 1-0 to Brazil in Tuesday night's other match.
"At the time I didn't know how important it was but we knew every goal would count and I wanted more than that in my own selfish way. I'm happy we could get that second spot," Kerr said in the post-match press conference broadcast on FIFATV.
When asked about the nature of her first two headed goals, despite her diminutive stature, the 25-year-old added: "I guess I grew up watching Timmy Cahill. I practice it a lot but I'm also gifted and they're my favourite kind of goals so I'm stoked."
Australia will now face Norway in the round of 16 and coach Ante Milicic said: "In the end, we won, convincingly, come second in a very difficult group and move forwards.
"Now we rest and recover and go forward to a difficult game against Norway."
Jamaica coach Hue Menzies admitted more preparation is needed ahead of the next World Cup so his side can hit the ground running.
The Reggae Girlz scored their first World Cup goal against Australia thanks to Havana Solaun but they were outplayed in a Kerr masterclass.
Menzies said: "We just didn't execute in the way we wanted to but we can't stop saying how resilient this group is. We kept playing and believing in ourselves.
"I want to make sure when we leave this programme it is in a better situation. We need to do a better job of preparing for the World Cup.
"We got a goal today and we should have got a couple more."