Four-time Olympic champion Simone Biles will open on the uneven bars when she returns to competition on Saturday night at the US Classic, her first gymnastics meet since the Tokyo Olympics.

The 26-year-old American has been on a two-year hiatus since struggling in Japan with the "twisties" -- a disorienting feeling while in mid-air that leaves gymnasts at greater injury risk when landing.

Biles, a 19-time world champion, was affected early in the Tokyo team competition, pulled out of the all-around plus the vault, uneven bars and floor exercise disciplines before taking bronze on the balance beam.

In what could be her first step on the road to next year's Paris Olympics, Biles will compete in the second session of Saturday's women's competition.

Biles will be the second gymnast on the bars in rotation one, then compete first on the beam in rotation two, sixth and last on floor exercise in rotation three and fifth on the vault in the final rotation.

After the opening session, which featured 16 of the 35 women in the competition, 17-year-old Joscelyn Roberson led the way with 54.050 points despite a fall on the uneven bars.

She had top scores on the vault (14.650), floor (14.000) and beam (14.300) while Zoe Miller led on bars with 14.750.

More experienced competitors will perform in the night session, including Biles and reigning Olympic all-around champion Sunisa Lee, who has battled a kidney-related health issue this year.

Biles performed well in each discipline during a Friday practice session, performing the difficult Yurchenko double pike vault during her workout.

Biles used the US Classic as her comeback meet in 2018 after taking a lengthy break following her gold-medal campaign at the Rio Olympics, which included all-around, vault, floor and team gold medals.

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