Fifteen world-class athletes, including last year's winner and rising stars, promise to make tomorrow's Macau International Marathon a two-hour battle against time and humidity. Kasirai Sita, 25, from Zimbabwe, who won in Macau last year and came sixth at the Two Oceans Marathon in Cape Town this April, is set to once again contend for the gold and the US$10,000 prize. Fierce competition is expected as 33-year-old Kenyan Benjamin Matolo, who won the international marathons in Macau in 2001 and Hong Kong in 2002, returns with hopes of recapturing the title. Last year in Macau, Matolo came in 11/2 minutes behind Sita. Among contenders competing in Macau for the first time is Adam Dobrzynski, 30, from Poland. He described the Macau marathon course as 'difficult' and 'hilly'. Dobrzynski's best time of 2:12:35 was set this October when he won the Kosice Peace Marathon in Slovakia, Europe's oldest international marathon. 'In Macau I'm not aiming for the personal best [time], because the humidity is too high,' he said. 'But I am hoping for a good place in the race.' The Pole also came second in the Nagano Marathon and sixth in the Prague Marathon this year. But Carlos Lopes, 1984 Olympics marathon gold medallist and a special guest invited to observe the Macau marathon this year, said humidity impacts each runner differently. 'That year when I competed in the Olympics in Los Angeles, it was 75 per cent humidity, like Macau, and the temperature was even 35 degrees Celsius, but I still won,' he recalled. Also invited to compete tomorrow is 19-year-old Pu Zhen, a native of Shandong Province, who said she was training lightly in Macau in order to adapt to the course. Pu, the only invited athlete from the mainland, came 12th in the Beijing International Marathon earlier this year. 'One thing I know is that I won't have time to play in the casinos,' she said. The marathon starts at 7am tomorrow from the Estrada da Baia de Nossa Senhora de Esperanca, near the Marina Infante Hotel in Taipa.