RIO DE JANEIRO • Simone Biles has Swarovski crystals on her torso and glitter around her eyes, so that she shimmers even before she dazzles.

She did not need the fake sparkle on Thursday night. The teenager, who has taken the Rio Olympics by storm, won the women's all-around title, the top-drawer event of gymnastics, by the incredible margin of 2.1 points.

To give that some context, it was a larger margin of victory than the combined margins from 1980 to 2012.

Biles' 15.933 on the floor made sure of the title with a total tally of 62.198. Her US team-mate Alexandra Raisman wept as she secured silver (60.098). The London 2012 bronze medallist, Russia's Aliya Mustafina, was third again (58.665).

By winning her second gold in Rio, after claiming the team medal earlier, Biles, who is the first woman to win three consecutive all-around world titles, etched her name alongside the greats of the sport like Nadia Comaneci.

The Romanian, the 1976 Montreal gold medallist, was the first gymnast to earn a perfect 10.

Biles, 19, coincidentally is coached by Romanian Martha Karolyi, who guided compatriot Comaneci to fame before defecting to the United States in 1981.

On Thursday Karolyi, who will soon retire after many years coaching the US' top gymnasts, predicted great things for her young prodigy.

"I'm sure she will be a big star. She'll be a millionaire," said the 73-year-old. "There are so many things she wants to do. She's such a happy, smiley girl with a positive attitude."

Biles, just 1.45m tall, was so dominant that she could have fallen twice and still romped to the all-around title.

Apart from a hop on the landing of her opening vault, the Texan gave a confident display of gravity-defying tumbles, twists and flips in her maiden Games .

"Congratulations @Simone_ Biles and @Aly_Raisman What a beautiful success...," tweeted Comaneci, who was among the spectators in the Rio Olympic Arena.

Biles scored highest on three of four rotations - beam, vault and floor - to keep on track for a record haul of five gold at one Games with finals on those apparatus to come.

Five golds would see her overtake Soviet gymnast Larissa Latynina (1956), Czech Vera Caslavska (1968) and Romanian Ecaterina Szabo (1984), who have all won four golds at the same Games.

She has already won more gold medals - 10 - in the World Championships than any other female gymnast in history.

"It (the gold) means so much to me because they (her maternal grandparents Ron and Nellie Biles) are the ones who brought me up. It's just extra motivation. I wanted to do it for them," said Biles.

Born in Columbus, Ohio, Biles moved to Texas at the age of three to be brought up along with her younger sister by Ron and Nellie.

The couple adopted the children after their mother was struggling with alcohol and drug addiction. Two other siblings were adopted by Ron's sister.

For Raisman, 22, silver was like gold behind a team-mate who is in another league.

"No one goes into this thinking they can beat Simone," she said. "I'm sure most people don't go into it (the men's 100m) thinking they can beat Usain Bolt either, so it's kind of the same thing."

But Biles dismissed talk of stardom. "I'm not the next Usain Bolt or Michael Phelps. I'm not a celebrity. I'm just the same Simone. I just have two Olympic gold medals now," she said.

But she is flattered by recognition from idols such as Comaneci: "I feel we're following in her footsteps. It's awesome that she retweets my tweets. It's so cool," said the champion gymnast.

AGENCE FRANCE-PRESSE, THE TIMES, LONDON