LONDON (AFP) - Jamaican sprint star Usain Bolt remained on track for a 12th world title after advancing to the final of the 100m at the World Championships in London on Saturday (Aug 5).

Defending champion Bolt, who brings the curtain down on his glittering career at the end of this season, was pipped in his semi-final in a photo finish by American Christian Coleman, who clocked 9.97 seconds.

Bolt and Coleman will be joined by respective teammates Yohan Blake, the 2011 world champion, and veteran Justin Gatlin, whose doping-tainted past again saw him jeered by the sell-out 60,000 crowd at the London Stadium.

South African Akani Simbine, in 10.05sec, won the first semi just ahead of Gatlin.

Blake raced to victory in the second in 10.04sec, a hundredth ahead of Britain's Reece Prescod.

Su Bingtian of China and Frenchman Jimmy Vicaut clinched the two best third-place finishers to round out the final scheduled for 1945 GMT.