The acrobatics that Simone Biles tries are so extreme and difficult that even when she does not execute to perfection, she still ends up on a world podium.

Biles had to be content with a silver medal on Saturday at the world championships - her 28th overall since she started her harvest a decade ago - after she over-rotated her signature Yurchenko double pike and fell backwards on the mat on landing.

Rebeca Andrade of Brazil denied Biles a 22nd world title by winning the vault competition ahead of the American superstar.

A day after she became the most decorated gymnast in history, Biles tried to claim back the title she last won in 2019 by performing her extremely difficult signature vault that nobody else does in the women's competition, and only a few men attempt.

Biles' second vault was an excellent Cheng to finish with a combined score of 14.549. Andrade was nearly flawless to snatch the gold medal by a margin of 0.201 points. Yeo Seo-jeong of South Korea took the bronze with 14.416.

Andrade said she was disappointed to witness Biles failing in her quest for perfection.

"I'm happy for my result, but sad about the fall because we know how much athletes train to do this vault," she said through a translator.

Asked whether she would try the Yurchenko double pike in competition, Andrade said it would be a "crazy" thing to do.

"I don't have the body for that," she added.

Biles became the first woman to do the Yurchenko double pike at the world championships during qualifying, and the vault is now named the Biles II because it was achieved in international competition. The 26-year-old American now has five skills named after her.

Biles, who has won a record 35 medals at the world championships and Olympics, has returned to competition this summer after a two-year break that she used to focus on her mental wellbeing following the Tokyo Olympics.