SHANGHAI, Sept. 28 -- OLYMPIC champion Liu Xiang has cooled talk of home-town heroics at today's Golden Grand Prix meeting in Shanghai on his return to competition four weeks after becoming China's first male track world champion.

Liu, who shoulders the burden of China's athletics hopes at next year's Beijing Olympics, chose to miss lucrative European tour events after winning the 110 meters hurdles world title in Osaka last month.

In his last outing in Shanghai before the Beijing Games, the world record holder and Olympic champion faces a stiff challenge from 20-year-old Cuban Dayron Robles, whose winning time of 12.92 seconds in Stuttgart last weekend equalled Liu's best time of the year.

"There are always many young athletes coming up to challenge you," Liu said before the race, sounding pleased to share the spotlight for once.

"I saw the video of Dayron Robles' performance in Stuttgart. He really did a great job. He is in better shape than me now," the 24-year-old said.

Liu will also be stretched by American Allen Johnson, the 36-year-old former Olympic and world champion he pipped at the same race last year.

Newly crowned world champion Tyson Gay, avoids a 100 meters rematch with world record holder Asafa Powell, with the Jamaican scheduled to race in a weaker 200 meters field.

Since losing to the American in Osaka, Powell has been unstoppable, lowering his own world best to 9.74 earlier this month.

American 400 king Jeremy Wariner and Russian pole vaulter Yelena Isinbayeva look likely to dominate their events, while Sanya Richards' absence from the women's 400 leaves the field open for Britain's world champion Christine Ohuruogu.