Daegu: Usain Bolt, global sport`s most marketable star, will make his bow at the 2011 world championships in heats for the men`s 100m on the opening day of action on Saturday.
The Jamaican defending Olympic and world champion kicks off his campaign to snag another sprint double when he takes to Daegu`s blue track at 1245 GMT in round one of the blue riband event.
Missing from the heats, however, will be his three main rivals, compatriots Asafa Powell (groin injury) and Steve Mullings (doping), and American Tyson Gay (hip injury).
Also in action on the opening day in South Korea is three-time defending world 200m champion Allyson Felix, who goes in heats of the 400m in her bid for a memorable double.
Felix has reigning world champion and fellow American Sanya Richards-Ross in her sights, although the latter put months of strife aside in storming to victory at the London Diamond League earlier this month in an impressive 49.66sec.
Jamaican trio Rosemarie Whyte, Novlene Williams-Mills and 2009 Berlin worlds silver medallist Shericka Williams will also be in the running along with Botswana`s Amantle Montsho.
The semi-finals of the women`s 400m are run on Sunday, with the final scheduled for 1205 GMT a day later.
Kenyan world record holder David Rudisha will open his campaign in the heats of the men`s 800m, looking for an easy ride through to Sunday`s semi-final before the final on Tuesday.
There are just two medal events on the first day of competition at the nine-day worlds, in the women`s 10,000m and marathon.
The latter event will be raced around a multi-lap (2x15km, 1x12.195km), largely flat street circuit.
In the absence of defending champion Xue Bai of China, compatriots Zhou Chunxiu and Zhu Xiaolin, Asian Games champion and silver medallist respectively, will lead the way.
Yoshimo Ozaki and Aselefech Mergia, defending world silver and bronze medallists, head up the Japan and Ethiopia teams, while Kenya will be led by London marathon third place-getter Edna Kiplagat, whose 2:20:46 makes her the fastest entrant in the field.
In the 10,000m, Ethiopian Meseret Defar will compete in her bid for a 5000-10,000m double, and will have Kenyan Vivian Cheruiyot, defending world champion at 5000m, in direct competition in the two events.
Another Kenyan, Linet Masai, the defending 10,000m champion, is also in the running.
The opening day also sees the first half of the decathlon, with the United States` high hopes of a strong podium showing falling on the shoulders of world leader Ashton Eaton and defending world champion Trey Hardee.