Jamaica's Elaine Thompson surprised even herself by storming to victory in the Rio Olympic women's 100 metres on Saturday as compatriot Shelly-Ann Fraser-Pryce failed in her bid to win a third straight title.

The 24-year-old was second slowest out of the blocks but powered away from the field over the last 50 metres to claim her first major individual title in 10.71 seconds, one hundredth of a second outside her personal best.

"When I crossed the line and glanced across to see I was clear I didn't quite know how to celebrate," she told reporters.

"I'm very excited I'm really happy, Jamaica has so many talented sprinters and to be only the second Olympic champion I'm really happy about that."

American Tori Bowie took silver in 10.83 while Fraser-Pryce, who was looking to become the first woman to win three successive gold medals in an individual athletics event, won bronze by a seven thousandths of a second in 10.86.

"I just wanted an opportunity to defend my title," said the 29-year-old Fraser-Pryce, who has been struggling with a toe injury this year.

"What I'm most happy about is that the 100m title is staying in Jamaica."

Usain Bolt, who have his title at an unprecedented track triple in the men's 100m on Sunday, was quick to congratulate the pair on Twitter, lauding Fraser-Pryce "for fighting and showing the heart of champ".

Marie-Josee Ta Lou of Ivory Coast could count herself exceptionally unlucky not to walk away with a medal after clocking the same 10.86 time as Fraser-Pryce but being denied a place on the podium by the rarely-resorted to thousandths measurement.

Bowie will, like Thompson, also run in the 200 metres in Rio and is determined to leave with a medal to match gold mascara she wore for Saturday's race.

"It's a little overwhelming, it's my first time here and I'm leaving with a silver medal," said the 25-year-old, who timed her dip finish to perfection.

"(But) I'm not giving up on me being a gold medallist here."

Thompson's victory will extend Jamaica's dominance of the event to 12 years by the time of the 2020 Tokyo Olympics, while Gail Devers was the last American champion in 1996 - Marion Jones won in 2000 but was stripped.

Bowie warned the Jamaicans that she was determined to break that dominance, however, and get the United States back on top of the podium.

"I've just got to get better at running this race," she said. "I only started running this race in 2014 so I'm only two years in. By next time around I'll be a real professional."