Sam Kerr bagged a brace, with Chloe Logarzo, Emily van Egmond, and central defender Clare Polkinghorne all finding the net in the rout.
The scoreline means the Matildas are all-but-assured of a place in the Olympics ahead of the second leg in Vietnam on Wednesday.
Australia coach Ante Milicic says his side will not lose focus in Wednesday's Olympic play-off in Vietnam despite a thumping first-leg win.
