In a fast, bruising encounter, they defeated their bitter local rivals New Zealand 24-17 watched by a noisy and partisan crowd.
While the try count was four to three in favour of Australia, two of the New Zealand touchdowns came late in the day and the margin of victory was more emphatic than the scoreline suggests.
Canada secured the bronze medals after powering their way past Great Britain 33-10 in the third-place play-off, with Ghislaine Landry crowning a dominant performance with two tries.
The outcome will have delighted an impressive clutch of watching Aussie VIPs, including International Olympic Committee (IOC) vice-president John Coates, former IOC vice-president Kevan Gosper and World Rugby chief executive Brett Gosper.
While the first half of the Olympic rugby tournament has now been successfully completed, however, Gosper junior probably wishes tonight’s crowd had matched the 22,000 drawn to the last Olympic rugby final at Stade de Colombes in May 1924.
On that long-ago afternoon in Paris, the United States men’s 15-a-side team beat France to win gold and retain their Olympic title, with Romania taking bronze.
A complex and long-drawn-out medals ceremony in Deodoro enabled six officials, including new IOC Athletes’ Commission President Angela Ruggiero, World Rugby President Bill Beaumont and Romanian IOC member Octavian Morariu to get in on the act.
Australia’s IOC vice-president John Coates had the great pleasure of hanging the gold medals around his victorious compatriots’ necks on this historic occasion.
It was also good to see World Rugby President Emeritus Bernard Lapasset, who piloted the sport’s successful campaign to return to the Olympics, taking part in the ceremony.
A terrific start to the sport’s new Olympic adventure; now bring on the men.