Jamaica's yam-powered Usain 'Lightning' Bolt hopes to become the first man since Carl Lewis [Images] in 1984 to win an Olympic sprint double on Wednesday.

- 'Insane' Usain dazzles the world

The man whose father says owes his speed to the local vegetable has already won the showpiece 100 metres final in swashbuckling style, thumping his chest before the finish.

If he also carries off his preferred 200m in Beijing's [Images] Bird's Nest at 10:30 p.m. (2000 IST) -- and nobody looks capable of beating him -- Bolt will not only equal the illustrious American.

He would also establish himself as the undisputed poster boy of the Beijing Games along with American swimmer Michael Phelps [Images] who won an unprecedented eight gold medals.

"I like to enjoy what I do," said the lanky Bolt, who breezed through his 200m semi-final late on Tuesday, playing up to TV cameras and taking a look round at competitors during the race.

"You can't be too serious in your job."

Bolt, who runs the 200m final the day before his 22nd birthday, faces a tough challenge though to beat Michael Johnson's 12-year-old world record of 19.32 seconds.

The Jamaican's best is 19.67.

Bolt's exploits have lit up his Caribbean homeland in the same way that Phelps's eight golds in Beijing, passing Mark Spitz's [Images] 1972 Munich record, have thrilled Americans.

While theirs have been the standout individual performances, it is team China's overall record that is wowing the world.

The hosts, who came second to the United States in Athens 2004, go into Day 12 of the Olympics [Images] with a commanding lead of 43 golds on top of the medal table.

China now look impossible to catch, even by traditional Olympics powerhouse the United States, who have won 26 golds in Beijing so far. China's Communist authorities are reaping the benefits of massive investment in a Soviet-style sports system.

"There is basically no worry about top spot," state news agency Xinhua said, the confident tone contrasting with official caution over China's prospects before the Aug. 8-24 Games.