Hong Kong's star cyclist Sarah Lee has advanced to the third round of the women's sprint at the Tokyo Olympics, needing a repechage race to make the cut.

Battling to stay alive in the competition, the 34-year-old defeated Madalyn Godby from USA thanks to a strong finish in her fourth race on Friday.

Lee was competing in the repechage race after she lost in the second round to Britain's Katy Marchant.

In the opening qualifying round on Friday, she was the ninth fastest out of 29 riders, with a time of 10.538 seconds in the 200m dash.

That's more than 0.2 seconds slower than Lea Friedrich from Germany, who came first and set a new Olympic record.

Lee then overcame a scare in the first round against Simona Krupeckaite from Lithuania.

She was trailing entering the final lap but used her typical strong finish to beat her 38-year-old opponent to the line.

On Saturday, Lee and 11 other riders will compete in two more rounds at the Izu Velodrome for a place in the semi-finals and final set for Sunday morning.

Also in the sprint event, Hong Kong's Jessica Lee failed to qualify for the knockout stages. She finished 28th out of 29 riders in a time of 11.232 seconds.

"My ability is some ways away from the top riders. I feel I performed okay. Tactically, my options were limited, I gave my all in the races," she said afterwards.

Also in cycling, Hong Kong's Leung Bo-yee and Pang Yao were among 15 teams taking part in the inaugural Olympic women's madison event. But the pair weren't able to finish the race because they were lapped twice by other riders midway through the event.

Meanwhile, one of Hong Kong's medallists in Tokyo, Grace Lau, will carry the SAR flag in the Games' closing ceremony on Sunday.

The 29-year-old clinched Hong Kong's first-ever Olympic medal in karate on Thursday when she took bronze in the women's kata.

This is by far Hong Kong's best Olympic Games ever, with one gold, two silver and two bronze medals.