Australia hustled hard early, had their first penalty corner in just the second minute and were in front after 13 minutes. Stacey Michelsen and Brooke Neal were unable to prevent Kathryn Slattery snapping a shot past goalkeeper Sally Rutherford.
The lead doubled eight minutes later when Slattery ran in from the right, managed to retain control and her shot from an acute angle unluckily bounced off Keddell to wrongfoot Rutherford.
However, Australia were unable to press on and the Black Sticks were level by halftime.
Michelsen and Sam Charlton set up the first goal for Charlotte Harrison, who was on hand to nudge it past keeper Ashleigh Wells, and olivia Merry got the equaliser, whipping in a slick shot after Kayla Whitelock had produced a fine cross from the right just before halftime.
Australia had a good period of pressure in the third quarter, but New Zealand had their chances, too. Pippa Hayward got the decisive goal in the dying seconds of the third quarter, after Gemma Flynn's fine, deep cross reached her on the run and her angled shot beat Wells.
Keddell and Charlton had outstanding defensive games, Michelsen and Whitelock were influential figures in the middle of the park, and Merry, Flynn and Anita Punt were key figures in much of New Zealand's best attacking work.
Australia and China will meet to decide third and fourth spots tomorrow.
Ireland will play India for fifth and six, after the Irish fought back from 3-0 to beat Korea 1-0 in a penalty shootout. India beat Canada 1-0, leaving the Canadians to play Korea for seventh and eighth.