Chinese superstar Liu Xiang faces a huge test of his Olympic credentials when he lines up against reigning 110m hurdles world champion Jason Richardson at Shanghai\'s Diamond League meeting on Saturday. The 2004 Olympic gold-medallist has hit form as he bids to erase his injury heartbreak of 2008 and will be backed by his home crowd as he faces America\'s Richardson as well as Aries Merritt, the newly crowned world indoor champion. Liu, who was forced out of the Beijing Olympics by an Achilles injury in front of a packed Bird\'s Nest Stadium, was second behind Merritt in March and cruised to victory at the World Challenge in Japan this month. \"I\'m very happy to be on my home field for the Shanghai Diamond League competition,\" Liu, 28, told a news conference on Friday. \"This time, each athlete has very strong power. For me, I just want to give full play to my training for the best performance.\" On Saturday, he can lay down an important marker against Richardson, who took gold in last year\'s highly contentious world championships final in Daegu, South Korea. Liu finished second after he was obstructed by Olympic champion Dayron Robles, who was disqualified over the clash. The Chinese heads a star-studded line-up in Shanghai, nearly two months before the Olympics get under way in London. \"It will be interesting to see how everybody performs,\" said Norwegian Andreas Thorkildsen, the 2008 Olympic javelin champion. The women\'s 200m is shaping up as a duel between Jamaican Olympic champion Veronica Campbell-Brown and American Carmelita Jeter, the 100m world title-holder, in a preview of the two countries\' rivalry at the Games. \"I do know it\'s going to be competitive in London. I\'m just going to train hard,\" Campbell-Brown said Thursday. Australian pole-vaulter Steve Hooker, the reigning Olympic champion, will hope to take another step forward, a week after qualifying for the Games following struggles with a knee injury and an alarming slump in confidence. \"I think I\'m doing very well towards London,\" he said. \"I\'m just looking to consolidate the work I\'ve done this year.\" Another star entrant is long-distance legend Kenenisa Bekele of Ethiopia, the current Olympic champion and world record holder for both the 5000m and 10,000m, which he will be seeking to retain in London this year.