RIO DE JANEIRO , BRAZIL - AUGUST 11: Simone Biles wins Gold and Alexandra Raisman wins Gold in the overall gymnastics competition during the Olympic Games on August 11, 2016 in Rio De Janeiro , . (Photo by Jonathan Newton / The Washington Post) (Jonathan Newton/The Washington Post)

Aimee Boorman, the first gymnastics coach to lay eyes on the transcendent Simone Biles, started crying before the last routine. She knew it was over.

Boorman has mentored Biles since she was 7, guiding her through three all-around world championships, watching her redefine the sport with peerless power, athleticism and elegance. This was no longer a competition. This was Biles’s punctuating moment, in her signature event, a floor routine that Boorman already could envision making every jaw at Rio Olympic Arena descend, albeit not as gracefully as a Biles landing.

“Just go out there and have fun like you usually do,” Boorman told Biles before her finale.

And after that, Biles took your breath and any lingering skepticism away. She won the women’s Olympic all-around gold medal with a finish only she is capable of: a full-twisting double layout, followed by the move named after her — a double layout with a half twist, with a stag leap for icing. By her third and fourth passes, it seemed like she was leaping to the rafters and landing so softly that not even an egg could crack beneath her.

Simone Biles leads a group of five fierce gymnasts representing the United States at the Rio Olympic games. (Ashleigh Joplin,Jayne Orenstein/The Washington Post)

The inevitable could not have been more thrilling.

Biles, a talent who seems from the future, posted a 15.933 on the floor exercise, the highest mark awarded Thursday night. With a total score of 62.198, she finished more than two points better than silver medalist Aly Raisman, her American teammate, and more than 3.5 points better than bronze medalist Aliya Mustafina. In gymnastics, it’s an astonishing margin of victory — one that made U.S. team coordinator Martha Karolyi, not one for hyperbole, declare Biles the best female gymnast ever.

“She’s a force of nature,” Karolyi said.

She’s so good that Raisman admitted, “I wasn’t reaching to get a gold. I knew Simone was going to win. I was just hoping that I would be able to get second, and it was very, very special because this was the very best I could do.”

Raisman has won five Olympic medals, three of them gold. But she has been around Biles too much to dream bigger. She knew it was over. Just like Boorman, she knew.

Asked when she thought Biles had control of the all-around final, Raisman said: “Everyone knew she was going to win, like, a couple of years ago.”

Inevitability confirmed, greatness verified, Biles turned human on us afterward. For as poised as she has been for months, she felt the pressure to live up to her legend. She is the three-time reigning world champion, but who remembers those titles? She needed to bring her excellence to this stage, her sport’s biggest, and join Mary Lou Retton, Carly Patterson, Nastia Liukin and Gabby Douglas on the list of Americans to win the women’s individual all-around in the Olympics. She needed this achievement to be worthy of the praise that Nadia Comaneci happily gives her.

When Biles waved to the crowd after her dazzling floor routine, she started crying. Boorman was still in tears. The moment was overwhelming, despite being expected.

“Every emotion hit me at once,” Biles said. “So it was just kind of a train wreck.”

That’s the only time Biles ever will be able to describe herself in that way. On this night, she had the best scores in three of four events. She started the night with a 15.866 in the vault. She put up a 15.433 on the balance beam. The only drama came after Biles scored 14.966 on the uneven bars, her weakest event. That allowed Mustafina to hold a slim lead after two rotations.

Biles didn’t panic, however. She is as gifted at processing and minimizing pressure as she is performing.

“It’s the Olympics, but if you think about it your brain’s going to fall out,” she said before the Games. “You’re going to freak out.”

It’s hard to freak out when you’re as relaxed as Biles. She’s comfortable in most every setting. She’s so confident that she talks about not thinking while competing and about “just going out there and tumbling.”

She’s instinctive. She can be the goofiest person in the world and then turn serious on command.

“She has this great ability to focus when necessary, and the rest of the time, she’s completely unfocused,” Boorman said. “So she doesn’t use it up. It comes in very short bursts. She uses it when she needs it.”

The new all-around Olympic champion admits she’s happier for Raisman than she is herself. She saw her teammate dig deep and nail her floor exercise to beat out Mustafina for the silver medal. At the end of a crowd-pleasing routine, Raisman burst into tears.

Biles went to Raisman, but she had to pull away quickly because she was about to start crying, too. That wouldn’t have been good for her up-tempo routine, which fittingly was the last performance of the event.

Later, after she wiped away her own tears, Biles sounded so nonchalant about winning that a reporter had to ask her whether she was happy with her performance.

“Well, obviously, yes,” Biles said, laughing.

But if she’s the greatest female gymnast of all time, you will have to ask someone else about it.

“I don’t know, but probably not me,” Biles said when asked the greatest question.

She’s not quite a 4-foot-9 Muhammad Ali in a stars-and-stripes leotard.

“I guess it depends on who you ask,” Biles said. “Anything you ask me, I’ll shove it away.”

So you ask Boorman, the coach who knows her best, the woman who has been along for every thrilling phase of this journey. Like any protective coach, Boorman got a little upset about the thought that all of Biles’s accomplishments would be rendered insignificant if she didn’t win the Olympic all-around.

And then the coach was able to slam anyone crazy enough to have had doubts.

“A lot of people said she won’t be the greatest until she wins the Olympic all-around,” Boorman said. “So . . . ”

Boorman took a hop back, extended her left arm and made an emphatic gesture.

“Mic drop!”

For more by Jerry Brewer, visit washingtonpost.com/brewer.