World Under-23 champion Bresset led from the gun and triumphed in 1:30.52.
The Beijing 2008 champion Sabine Spitz of Germany was second, 1:02 behind, with Georgia Gould of the USA third, six seconds further adrift.
Spitz and Bresset were in the front group as the Frenchwoman went through the start-finish line with a lead of four seconds with three laps to go.
Spitz went over her handlebars on a steep rocky section known as Deane's Drop as Bresset went further clear.
Bresset appeared unstoppable as she passed through the two-laps to go marker in 1:40, with Spitz 33 seconds adrift.
With one lap to go, Bresset led by 57 seconds, and she continued to press on for victory.
The 23-year-old Bresset said: 'I'm very happy. It's amazing to win today. I hoped to win a medal and a gold medal is unbelievable.
'I started well, I took the front of the race and I managed it well.
'When I had a gap I told myself: "Now, I should go". I led until the finish and I'm very content.'