The Matildas flew out of the blocks as Katrina-Lee Gorry produced a nice cut-back for co-captain Lisa De Vanna to open the scoring just two minutes after kickoff.
The Australians extended their lead to 3-0 at half-time thanks to Clare Polkinghorne and Alanna Kennedy goals from two Elise Kellond-Knight corners.
It was more of the same in the second-half as Alen Stajcic's side sought to better their goal-difference.
Kyah Simon got the fourth goal of the match finishing first-time from a delightful through-ball by the excellent Stephanie Catley.
Five minutes later Michelle Heyman got on the scoresheet with a header from an Emily van Egmond corner as set-pieces continued to be an effective outlet for Australia.
Heyman got her second goal to make it 6-0 in the 66th minute with a composed outside-of-the-boot finish when she beat the offside trap to go one-on-one with Zimbabwe's substitute keeper Lindiwe Magwede - Van Egmond again the provider with a well-timed pass.
Msipa Emmalulate scored Zimbabwe a consolation goal in stoppage-time - a fine finish in off the post on a counter-attack as Australia bombed forward seeking more goals in a bid to overtake Germany to second spot in the group.
It wasn't to be, 6-1 the final score, but the Matildas won their must-win game and progress to the knockout stage where they will face hosts Brazil.
Meanwhile, The United States women's football team will come up against former coach Pia Sundhage in the quarter-finals, after Sweden booked their place in the last eight on Tuesday.
USA had already qualified from Group G prior to their below-par display in a 2-2 draw with Colombia, which featured a goalkeeping blunder from veteran Hope Solo.
Elsewhere, France earned second place behind the US, beating New Zealand 3-0 to earn a last-eight meeting with Canada, who maintained their perfect record with a 2-1 win against Germany, the next opponents for China.
Sweden drew 0-0 with China in their final group game - a result that saw both teams progress behind Group E winners Brazil, whose match against South Africa also finished goalless.
Additional reporting: Omnisport