Gymnastics superstar Simone Biles' quest to become the greatest female Olympian in Tokyo has taken a bizarre twist, after she dropped out of the women's team event after one vault.
After a disappointing attempt in the first rotation, the American was signified by an 'R' on the competitor list before the bars began, indicating she would not continue in the competition.
The International Gymnastics Federation confirmed she would play no further part in the team event, but said she would still receive a medal, if the heavily favoured US ended up on the podium.
Biles has remained at the venue, wearing her COVID-19 mask, so her withdrawal is unlikely to be related to the coronavirus.
Reports suggest she injured a foot during her vault attempt, with resulted in a disappointing score of 13.766, worse than all three Russian rivals and both her US teammates in the first rotation.
Biles was replaced by reserve Sunisa Lee for the uneven bars, with USA trailling Russian Olympic Committee after two disciplines.
USA Gymnastics confirms Biles withdrew with a "medical issue" that will be reassessed daily to determine whether she will contest individual all-around and apparatus finals.
But her post-competition comments suggest the problem was more mental than physical, with Biles insisting she was not injured, "just a little injury to my pride".
"We're going to see about Thursday," she says. "I have to focus on my mental health.
"I just think mental health is more revelant in sports right now. We have to protect our minds and our bodies, and not just go out and do what the world wants us to do."
Biles arrived at Tokyo with the world at her feet, hoping to improve on her performance at Rio five years ago, when she won four gold medals and a bronze.
The 19-time world champion helped USA to second-placed qualification - behind ROS - in the team event, leading the all-around and vault preliminaries. Biles was also the only gymnast to qualify for all four apparatus finals.
Winning the six golds on offer in Japan would have lifted Biles to 10 - one more than Russian gymnast Larisa Latynina's women's record of nine gold medals won over Melbourne 1956, Rome 1960 and Tokyo 1964 - and confirmed her status as the greatest gymnast of all time.
It would also have marked the largest number of gold medals won by a woman in any Olympic sport.
Only Michael Phelps, with his 23 swimming golds, has won more. Biles can still match four athletes on nine - Latynina, swimmer Mark Spitz, and track and field athletes Paavo Nurmi and Carl Lewis.
Without her, the US team finished second behind the Russians, with Biles the first to cross the floor to congratulate the winners.
Her departure was the second Olympic shock on Tuesday, with Japan tennis hope Naomi Osaka eliminated from the women's singles by Czech Marketa Vondrousova in the third round.
Osaka had withdrawn from the French Open and did not contest Wimbledon in recent months, citing the need for a mental break from the game.