Biles is the first woman ever to pull off the move on floor during the competition.

Simone Biles has made history as the first woman ever to pull off a triple double on floor during the U.S. Gymnastics Championships.

READ: Simone Biles Is An Olympic Superhero In New Art Tribute

Biles said that the triple double, which is made up of a double back flip with three twists, is "the hardest move in the world," and according to the New York Times, "The triple double is a skill that, until this point, had been done only on the men’s side, where it is still rare. None of the men at the national championships are expected to try one, and most of Biles's competitors can't even do a double double."

The 22-year-old gymnast had attempted the move during her floor routine at the championships on Friday but had an uneasy landing when she had to put both hands on the ground to steady herself. She then successfully pulled off the move on Sunday after she attempted it again and stuck the landing.

Biles also made history as the first woman to ever land a double-twisting somersault on the balance beam.

She received a gold medal on floor, vault, and beam, as well as third place on bars. She also won the U.S. all-around title, making this the sixth time she's received the award.