It was a tense playoff match, with several yellow cards being held out by referee Matt Rodden, who officiated his 100th game.
Etene Nanai-Seturo opened up the scoring for New Zealand, making a huge bust up the midfield to leave defenders in his wake.
Tone Ng Shiu then made a superb break and popped a chest pass to Akuila Rokolisoa who scored under the posts. Caleb Clark made two brilliant try saving tackles in the first spell, however he was sent to the sinbin for the second tackle because the ref deemed that he was off his feet.
Australia capitalised on their advantage and scored two quick tries to level the score 14-14 at half time.
New Zealand composed themselves in the second half, and when Australia had a man in the bin, William Wawbrick passed a great offload to Tim Mikkelson who scored on the left flank. The toing and froing continued, with Australia replying in quick succession. But a missed conversion made the difference and the All Blacks Sevens managed to hold on for a 21-19 victory.
Earlier in the day, New Zealand went down 17-0 to South Africa in the semi-final. South Africa went onto win the final in extra time, 29-24 over Fiji.
In the overall standings, the All Blacks Sevens still lead with 93 points, but South Africa have closed the gap to just five points, while Fiji are in third place with 72 points.
Tim Mikkelson had a tournament to remember as he became the most capped All Blacks Sevens player ever and he also moved to third on the all-time top try scoring table, with 232 tries.
The series moves to Vancouver next weekend, with the draw to be confirmed in the coming days.