HONG Kong's number one triathlete Ian Rayson faces a stiff task completing his second straight win on the newly formed Asian circuit with top Australian Simon Knowles coming for the Puma international championship in May. Rayson won the opening race of the nine-event series in India last month but the opposition will be stronger in the Hong Kong event, to be held for the first time at Tai Mei Tuk in the New Territories. Race favourite should be Knowles, who showed a tonne of consistency on the Australian professional circuit in the 1992-93 season when he made the top four in all 11 races. The 24-year-old Australian posted five wins, four second placings, one third and one fourth - results which earned him the accolade of Australian Triathlete of the Year for 1993. Another top overseas contender is Malaysian ace Razzani, who has fought some absorbing battles in the last two years with Rayson. The local triathletes, however, are hoping that knowledge of the course will give them an advantage. ''We will be doing the swim for the first time at Plover Cove but there is a biathlon warm-up race over the run and cycle course on April 16,'' said Tony Chui Kam-tong, who finished seventh in India. ''The most difficult part of the actual triathlon race should be the swim-bike transition because the distance between the water and the bike transition area is about 1,500 metres, of which 300 metres is a very steep climb. We'd have to pace ourselves very well when running to our bikes otherwise we would be too weak to get on the machines.'' Competitors from China, Taiwan, Thailand, India and the Philippines will also be here.