Tom Burton spent two days coming up with a plan to stop his main rival from forcing him into a bad start in the final Laser medal race.
It proved time well spent as he turned a "one in 10" situation into Australia's first gold medal in sailing at the Rio Games.
Croatian Tonci Stipanovic was 10 points ahead of Burton in first and promised to push the Australian to the back of the fleet from the start of the double points race.
Instead Burton pulled a move on the start line to force Stipanovic to take a penalty turn while the Australian pushed on to claim gold.
"We had a lot of talks the last two days about a bit of a catch-and-release," Burton said.
"It couldn't have come off any better, it was perfection."
While Stipanovic was stuck back in ninth, Burton counted off the boats one by one as he moved up the fleet.
"I needed to come third to win, and I could see in front of me there were three boats in front of me, so I needed to pass one," he said.
Burton finished third to claim gold, Stipanovic won silver, and New Zealand's Sam Meech got bronze.
The Australian admitted he was a long shot of getting the result.
"I was even talking to my coach before the race thinking `if we did this 10 times how many times would I be able to pull it off' and he said `nah 25 per cent'," Burton told the Seven Network.
"And I said `I think one out of 10'. And all you need is the one, and that's exactly what I put out today."
Stipanovic said he was caught out by a tough decision from the jury at the start.
"The jury boat passed too close to us with a bit of speed, he made waves, the waves pushed me onto Tom, we touched, and then jury decide to give me a penalty," he said.
Stipanovic, who claimed Croatia's first ever sailing medal, said Burton had sailed well all regatta.
"I think he deserves it, especially with my bad sailing here in the medal race," he said.
The win makes it two gold in a row in the Laser for Australia, after Tom Slingsby won in London 2012.