LONDON -- Pulling away from the pack with every long stride, Usain Bolt crossed the finish line and wagged his right index finger.

Yes, he's still No. 1 in the 100-meter dash. Maybe not better than ever, but Bolt is definitely back.

Only sixth-fastest of the eight runners to the halfway mark Sunday night, Bolt erased that deficit and overwhelmed a star-studded field to win in 9.63 seconds, an Olympic record that let him join Carl Lewis as the only men with consecutive gold medals in the marquee track and field event at the Summer Games.

"Means a lot, because a lot of people were doubting me. A lot of people were saying I wasn't going to win, I didn't look good. There was a lot of talk," Bolt said. "It's an even greater feeling to come out here and defend my title and show the world I'm still No. 1, I'm still the best."

Ever the showman, the Jamaican kept right on running for a victory lap that included high-fives for front-row fans, a pause to crouch down and kiss the track and even a somersault. Thousands in the crowd chanted the champion's name: "Usain! Usain! Usain!"

"I've said it over the years, that when it comes to the championships, this is what I do," Bolt said. "It's all about business for me."

Bolt's training partner and Jamaican teammate, world champion Yohan Blake, won the silver in 9.75, and 2004 Olympic champion Justin Gatlin of the U.S. took the bronze in 9.79.

"It just feels good to be back," said Gatlin, who served a four-year ban after testing positive for excessive testosterone.

Everyone in the final broke 10 seconds except former world-record holder Asafa Powell of Jamaica, who pulled up with a groin injury.

At Beijing four years ago, the 6-foot-5 Bolt electrified track and field, winning gold medals in world-record times in the 100, 200 and 4x100 relay -- something no man had ever done at an Olympics. His 100 mark of 9.69 set there, the one that came despite some slowing down for celebratory chest-slapping, only lasted until the next year's world championships, when he lowered the record to 9.58.

Usain Bolt celebrates winning the gold medal after running the 100-meter dash in an Olympic-record 9.63 seconds. Stu Forster/Getty Images

But The World's Fastest Man had been something less than Boltesque since then, in part due to a string of minor injuries to his back and legs. In 2010, he lost to Tyson Gay, the American who's a past world champion and cried inconsolably after ending up fourth Sunday in a time (9.80) that would have been good enough to win every Olympic 100 gold medal other than the past two.

A false start knocked Bolt out of the 100 at last year's world championships, creating an opening for Blake. Then came recent, much-discussed losses to Blake in the 100 and 200 at the Jamaican Olympic trials.

"The trials woke me up. Yohan gave me a wakeup call," Bolt said. "He knocked on my door and said, 'Usain, wake up! This is an Olympic year."

Bolt, a fast runner who likes to drive fast, too, was involved in a wee-hours car crash in Kingston in June -- not the only auto accident he's been in. His publicist played down the seriousness of the latest episode, but the hand-wringing in Jamaica intensified after the poor performances at the trials a few weeks later.

Bolt never let any of that affect him in London.

"I had to show the world I'm the greatest," he said.