TOKYO: Puerto Rico's Jasmine Camacho-Quinn won the women's 100 metres hurdles gold on Monday, blitzing the field despite hitting one hurdle to finish in 12.37 seconds at Tokyo's spectator-free Olympic Stadium.

American world record holder Kendra Harrison won silver in 12.52 and Jamaican Megan Tapper took bronze in 12.55.

Camacho-Quinn exploded off the blocks and strode shoulder-to-shoulder with Harrison, accelerating through the finish to win her first-ever Olympic medal and Puerto Rico's first of the Tokyo Games.

Harrison and Tapper faced an agonizing wait as officials analysed their photo finish, with the bronze medal-winner looking up at the screen and saying "pray Jamaica," as she awaited the results.

The victory capped a dazzling performance in Tokyo for Camacho-Quinn, who broke the Olympic record in her semi-final a day earlier.

She told reporters she nearly fell during the final, five years after she crashed out of her semi-final in Rio de Janeiro.

"I was really running for the record, I hit the hurdle - but everything happens for a reason," she said. "I crossed the line like, 'wait - I just won!'"

It was the first Olympic gold medal in athletics for Puerto Rico and Camacho-Quinn said she hoped her achievement could inspire children on the Caribbean island.

"I'm just glad I'm just that person to do that," she said, crying tears of joy. "I'm pretty happy right now."

The race was the last of the morning programme at the stadium, where competitors were once again greeted by Tokyo's blistering heat.

The athletics competition will resume later on Monday.