BEIJING, China (AFP) — Usain Bolt bids to retain his title as the world’s fastest man on day two of the world athletics championships on Sunday.

The Jamaican easily qualified for the 100 metres semi-final along with American rival Justin Gatlin, who set the fastest qualifying time of 9.83sec.

But all eyes will be on Jamaican superstar Bolt, who faces a serious challenge from American Gatlin in a blockbuster clash in Beijing, where Bolt famously blasted to triple gold at the 2008 Olympics.

“I was just trying to execute and save as much energy as possible,” Bolt said after winning his heat. “I’m in wonderful shape.”

Gatlin, 33, who has twice failed doping tests in the past, has clocked this season’s fastest time of 9.74 seconds, while world record holder Bolt returned from injury with a 9.87 in London last month.

Such has been the towering Jamaican’s complete dominance of sprinting since 2008 that astonishingly the only time he failed to land a major title was when he was disqualified for a false start in the 100m in Daegu four years ago.

Bolt’s eye-popping world record of 9.58, set in Berlin in 2009, would appear safe but with allegations of widespread doping engulfing the sport, his showdown with Gatlin is being seen by some as a symbolic struggle of light versus dark.

Jamaica’s double Olympic champion Shelly-Ann Fraser-Pryce begins her quest to win an unprecedented third women’s 100m world title in the heats later today.

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