Bolt completes double in Rio

The incomparable Usain Bolt once again proved utterly unbeatable on the Olympic track on Thursday, powering his way to a third straight 200 meters gold and remaining on course for an extraordinary "triple-triple" of sprint titles.

The Jamaican simply laid waste to the best of the rest in the sprinting world to win his eighth track gold medal in what he has said will be his last individual race at the Olympics before his retirement next year.

Bolt's time of 19.78 seconds was the slowest of his four straight world championship and three Olympic triumphs over 200 meters but it certainly did not dampen the celebrations.

He struck his signature lightning bolt pose to a huge cheer from the crowd and draped Brazilian and Jamaican flags over his shoulders as he performed his lap of honor to chants of "Usain Bolt! Usain Bolt! Usain Bolt!".

"I don't need to prove anything else. What else can I do to prove to the world I am the greatest?" Bolt told reporters.

"I am trying to be one of the greatest. Be among (Muhammad) Ali and Pele. I hope to be in that bracket after these Games."

His place in that pantheon is probably already assured but Bolt will return to the track for the 4x100m relay on Friday - two days before his 30th birthday - looking to complete the sweep of all three sprint titles at three successive Olympics.

Canadian Andre de Grasse, who also won bronze behind Bolt in the 100m, finished second in 20.02 to claim his second sprint medal of the Games and establish himself as the heir apparent to the Sprint King.

"I love competing against him," the 21-year-old said of Bolt. "It's an honor to be a part of history, of what he’s accomplished in his career ... but overall, if his time is up I guess a new person has to come in there."

Christophe Lemaitre of France was ecstatic with his bronze medal after edging out a shattered Adam Gemili of Britain in a photo finish. Both were awarded the same time of 20.12.

Even the prospect of witnessing a once-in-a-century athlete in his pomp was not enough to fill the Rio Olympic Stadium but what the crowd lacked in numbers, they made up for in noise as they welcomed Bolt to the track like a rock star.

The great showman responded in kind by playing air guitar and swaying to the music while smiling and nodding straight into the TV camera.

Beaten only once in nine years in his favorite event, the Jamaican had said he thought the world record of 19.19 he set at the 2009 world championships in Berlin was within reach. It was not to be.

Head down and hands pumping away as he built up speed over the first 30 meters, Bolt rounded the bend with a clear lead but was unable charge to the line as fast as he wanted, even if he did finish three meters clear of De Grasse.

"I ran hard around the turn," said Bolt. "On the straight, my body didn't respond. I'm getting old."

Lemaitre, the first white man to run under 10 seconds, raised his hands above his head and fell back onto the track as the scoreboard confirmed he had taken the bronze.

"It was an unbelievable moment," said the 26-year-old. "I knew I could but I also knew it would be unbelievably hard. I'm so grateful to get this medal."

Gemili was left shattered by missing out on a medal by three thousandths of a second.

"I put so much into that run but lost my form at the end," the Briton said. "I'm absolutely gutted."

Churandy Martina of the Netherlands, timed at 20.13, was only another three thousandths of a second behind Gemili, while American former 400m champion LaShawn Merritt was sixth in 20.19.

The 200 meters aside, there was success aplenty for the United States on Thursday.

Dalilah Muhammad won the women's 400m hurdles after Kerron Clement had taken the men's gold, while Ryan Crouser hurled the longest throw of his life to win the men's shot put.

Croatian Sara Kolak won javelin gold to dash Czech Barbora Spotakova's dreams of becoming the first woman to win three consecutive gold medals in the same individual athletics event.

Ashton Eaton has become almost as dominant in the decathlon as Bolt is in the sprints but the American was happy to defer to Bolt after retaining his title.

"We are in the era where Usain Bolt ends, and the young kids inspired him are just getting started," he said.

"I had the pleasure of being in the same era as Usain Bolt. I mean, the guys' last name is Bolt, he's the fastest man ever, you can't write a story like that."