Usain Bolt returns to China for the first time since his triple-gold Olympic feat to launch his 200-metre season tomorrow while hurdler Liu Xiang looks for redemption in his hometown.
Bolt comes to the Shanghai IAAF Diamond League meet after running 9.86 seconds to win his season-opening 100m at South Korea's Daegu Pre-Championships Meeting on Wednesday.
The 100m and 200m world record holder is being pursued by American Tyson Gay and fellow Jamaican Asafa Powell, who have both made it clear they aim to beat him this year.
But with Gay and Powell staying away from Shanghai, Bolt is expected to dominate tomorrow's race despite calling this an "off season" when he intends to get as much rest as possible ahead of next year's World Championships.
Bolt's 200m race will help set the stage for three upcoming Diamond League showdowns with Gay, who fired a new warning in Bolt's direction by shattering the 44-year-old straight line 200m world record on Monday.
Shanghai's fiercest race is expected to be the men's 110m hurdles as Chinese star Liu seeks to regain world-class form after finishing seventh in his international return at the World Indoor Championships in March.
Barbados's Ryan Braithwaite, the 110m hurdles world champion, and American David Oliver, who won bronze at the indoor championships, will challenge Liu on his home turf.
But Olympic champion Dayron Robles, of Cuba, has decided to skip the meet, preventing a showdown with Liu.
Liu, who became the first Chinese man ever to win Olympics track and field gold at the 2004 Athens Games, is striving for his one-time record-breaking form after an achilles heel injury force him out of the 2008 Beijing Olympics.
US sprinter Carmelita Jeter also returns to Shanghai where she ran the best women's 100m time of last year at 10.64 seconds. She competes against world champion Shelly-Ann Fraser, of Jamaica, for another victory in Shanghai.
A total of 15 world champions will compete in Shanghai at what organisers say is the highest level competition ever held in China.
The Diamond League awards points depending on performances throughout the 14-event programme with the winners of the 16 meets taking home a diamond trophy and a cash prize.