Fellow American Carey, 21, scored 14.366 to seal a first Olympic medal, with Italy's Vanessa Ferrari taking silver ahead of Japan's Mai Murakami and Russian Angelina Melnikova, who shared bronze.

"I feel really great about tonight. All my hard work has paid off and this is all I ever dreamed of," said Carey, who finished last in the vault final.

Biles posted a photograph of Carey as a gold medallist along with the tag "Go Jade" on her Instagram.

Biles has only participated in all-around qualifying and the vault in the team event at the Tokyo Games, saying she wanted to protect her mental health.

The 24-year-old, who has 23 gold medals from world championships and Olympics, withdrew from all individual events so far after struggling to synchronize mind and body in training.

However, the American, who won four golds at Rio 2016, has decided to compete in Tuesday's balance beam final.

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

Despite her absence, the US has so far claimed five medals in the women's gymnastics at Tokyo.

China's Liu Yang earlier produced a near flawless performance to seal gold in the men's rings competition.

He scored 15.500 points with compatriot You Hao taking silver on 15.300 and Greece's Eleftherios Petrounias, the 2016 rings champion, claiming bronze.

South Korean Shin Jeah Wan triumphed in the men's vault final with Russian Denis Abliazin having to settle for silver for the second straight Games.

He had the same score of 14.783 as the South Korean, who won on a tiebreak as he had the single highest vault score.

Artur Davtyan secured bronze for Armenia, the country's first ever Olympic gymnastics medal.

Australian Associated Press