Marcus Fraser fired a brilliant 63 to take the first-round lead as golf returned to the Olympic Games for the first time in 112 years on Thursday.
Local favourite Adilson da Silva had the honour of hitting the first Olympic golf shot since 1904 but after that it was the Fraser show, as the Australian made nine birdies to get to eight under and open up a three-shot lead over Henrik Stenson and Graham DeLaet.
Great Britain's Justin Rose also gave the crowd something to cheer about as he made the first hole-in-one in Olympic history on the par three fourth, and he was four behind Fraser alongside Grégory Bourdy, Rafa Cabrera Bello, Alex Cejka and Thomas Pieters.
World Number 190 Fraser was playing this week because four of his countrymen withdrew from the event and he found it hard to hide his delight after grabbing his Olympic opportunity with both hands.
"I was watching the World Rankings pretty much every day," he said. "To see at one point I was in the team, at one point I was out.
"With the locker room feel, it definitely has a completely different feel to it this week and something that's really special. It's something that I'll look back on later in life and really appreciate.
My kids can say their dad is an Olympian and that was a big part of wanting to do it, for them. They will be waking up in the morning in a state of shock that their old man is leading the Olympics - Marcus Fraser
"At the moment I have the Olympic record, which is pretty cool. Hopefully that will last for the whole week. I never thought I would be talking about myself as an Olympian, that's for sure."
Fraser took advantage of the par five first and, after a bogey on the next, went on a run of four birdies.
An approach to four feet and excellent tee-shot set up gains on the third and fourth before the putter got hot as the Maybank Championship Malaysia winner holed from 23 and 25 feet on the fifth and sixth.
A beautiful approach to the par five tenth set up another birdie and a further gain on the 13th had Fraser six under. The final three holes all offer up birdie opportunities and the 38 year old capitalised on the 16th and 18th to open up a three-shot gap to DeLaet.
The Canadian - trying to defend the title for his country after George Lyon won gold in 1904 in St Louis - made six birdies with a single dropped shot in his 66.
Swede Stenson was out in the final group of the day and he had a single bogey on his card at the 13th as he looks to add Olympic glory to his stunning Open Championship triumph last month.
Spain's Cabrera Bello was playing alongside Stenson and despite having a double-bogey on the card, he finished birdie-birdie-birdie to fire himself up the leaerboard.
Rose also birdied the last with three other gains and two bogeys accompanying his ace, while Frenchman Bourdy dropped a single shot on the 16th.
Belgium's Pieters used his distance off the tee as he birdied the par five first, tenth, and last while also driving the par four third for another gain. He also made birdies on the sixth and ninth with dropped shots on the eighth and 14th.
Pieters' team-mate Nicolas Colsaerts was then at three under alongside South Korean Byeong-hun An, with Spaniard Sergio Garcia, Germany's Martin Kaymer, Swede David Lingmerth and Italy's Matteo Manassero among those a shot further back.
