After pulling out of her first events with the "twisties", a disorientating mental block, Biles was included on the list of eight finalists for Tuesday's closing beam competition.

"We are so excited to confirm that you will see two U.S. athletes in the balance beam final tomorrow - Suni Lee AND Simone Biles!! Can't wait to watch you both!" tweeted USA Gymnastics.

Biles came to Tokyo seeking five gold medals to equal the Olympic all-time gymnastics career record of nine, but her mental struggles have wrecked those plans.

Elsewhere on day 10 in a steaming Japan, Jasmine Camacho-Quinn claimed Puerto Rico's first athletics gold in Games history, and Greece's Miltiadis Tentoglou won the men's long jump.

Camacho-Quinn, 24, who had set an Olympic record 12.26sec in the semi-finals of the women's 100m hurdles, surged home to claim her first major title in 12.37sec.

World record-holder Keni Harrison of the United States took silver in 12.52sec while Jamaica's Megan Tapper claimed bronze.

"For such a small country it gives little people hope," said Camacho-Quinn. "I am just glad I am the person to do that."

'Double-double' bid

In the men's long jump, European champion Tentoglou leapt a best of 8.41 meters on his sixth and final attempt to snatch victory from Cuban Juan Miguel Echevarria, who also managed 8.41m but had an inferior second-best jump.

Defending 200m champion Elaine Thompson-Herah continued her audacious bid for an unprecedented Olympic women's sprint "double-double" as the Jamaican advanced to the 200m semifinals.

Shelly-Ann Fraser-Pryce, outgunned by her teammate in the 100m final, also progressed, but 100m bronze medalist Shericka Jackson, also of Jamaica, failed to make it through after inexplicably slowing with 40 meters to run.

Christine Mboma of Namibia, who has to run the distance because her high testosterone levels mean she is barred from the 400 m, clocked the fastest time, 22.11sec, to finish ahead of hot US favorite Gabby Thomas.

Belarusia's Kristina Timanovskaya was supposed to be competing in the 200 m heats but instead spent the night holed up in a Tokyo airport hotel.

Timanovskaya alleged that her team was attempting to send her home after she criticized Belarus's athletics federation for entering her into a relay race without giving her notice.

Poland has granted a humanitarian visa to Tsimanouskaya, Poland's deputy foreign minister said Monday.

Tsimanouskaya "is already in direct contact with Polish diplomats in Tokyo. She has received a humanitarian visa. Poland will do whatever is necessary to help her to continue her sporting career," Marcin Przydacz wrote on Twitter.

Przydacz said Tsimanouskaya had turned to Poland for help out of her "very difficult" situation and was "safe on the grounds of our embassy" in Tokyo, news channel TVN24 reported.

Tsimanouskaya’s husband told AFP on Monday that her wife would likely travel to Poland, adding he himself had left Belarus.

"She will likely go to Poland," Arseny Zdanevich told AFP from the Ukrainian capital Kiev where he said he had fled to. He also said that he was hoping to join his wife "in the near future."

Distance runner Sifan Hassan fell in her 1500 m heat but picked herself up to finish first -- keeping alive her hopes of an unprecedented Olympic treble of 1500 m, 5,000 m and 10,000 m.

Hassan will run in the women's 5,000 m final at the Olympic Stadium later Monday, with medals also up for grabs in the women's discus and the men's 3,000 m steeplechase.

Away from the action, US shot putter Raven Saunders has risked disciplinary action after making the first protest on a medal podium of the Olympics.

The 25-year-old African-American athlete crossed her arms in an "X" gesture during Sunday's medal ceremony after claiming silver. Podium protests are banned at the Games.

Transgender first

Weightlifting is in the spotlight on Monday because of the participation of New Zealand's Hubbard.

The 43-year-old, who was born male and competed as a man before transitioning, makes her Olympic debut in the women's +87kg category.

Later in Tokyo, China's reigning Olympic champion Chen Long faces formidable Dane Viktor Axelsen in the men's badminton final after Indonesia won the women's doubles.

Track cycling started with a bang as the German team smashed Britain's world record in women's team pursuit qualifying ahead of the team sprint finals later at the Izu Velodrome.

China's Liu Yang won gymnastics' men's rings, and China beat Germany in the women's team sprint final as the track cycling competition got under way.

Women's soccer is also reaching its closing stages with Megan Rapinoe's USA, the world champions, taking on Canada while Australia plays Sweden, runner-up at the 2016 Rio Olympics.