Hong Kong's third-ranked men's singles player, Yohan Hadikusumo Wiratama, caused one of the shocks of the tournament when he became the first player from the SAR to defeat Indonesia's former world number one Taufik Hidayat, knocking him out in the second round of the Hong Kong Open at the Queen Elizabeth Stadium. Wiratama, ranked 39th in the world, defeated the 12th seed 15-7, 2-15, 17-14 yesterday. The 26-year-old, who arrived in Hong Kong from Indonesia in 2001, saved a match point at 14-10 down before eliminating the Asian Games and Indonesian Open champion. 'We've not beaten this guy before. We had chances but we've never worked out how to beat him, how to win those last few points,' said Hong Kong head coach Chan Chi-choi. 'Taufik is world class, one of the world's top players. He's not easy to beat.' The Hong Kong squad know that very well, having seen their top singles player Ng Wei eliminated by Hidayat in the semi-finals of the Asian Championship and the quarter-finals of the Japan Open. However, since September's Danish Open, Hidayat has found himself outside the confines of the Indonesian squad following a clash with coach Joko Suprianto. 'Since Denmark I haven't had a coach. I hope to go back to the national team next year in time for the Olympics,' said the 22-year-old, who has slumped down the rankings from third in July to 14th, but still believed he should have won. 'It's my fault. To lose from 14-10 is my fault. I know Yohan's game, I've trained with him, but I didn't have the concentration.' Hidayat wasn't the only men's seed to suffer a shock defeat on the fourth day of the tournament. World number one Chen Hong lost to fellow mainlander Bao Chunlai for the first time in international competition, 13-15, 15-5, 15-12. In today's quarter-finals he faces 18-year-old Indonesian Simon Santoso, who accounted for both South Korean fifth seed Shon Seung-mo and Denmark's Peter Gade, who was seeded 16. Hong Kong, having lost two of their men in round two - Agus Hariyanto and 20-year-old Hung Yuk-wong were beaten by the seeded Malaysian brothers Hafiz and Roslin Hashim - then saw their top-ranked player Ng Wei beaten in round three by seventh seed Anders Boesen. Ng never recovered from an anxious start, losing to the Dane for the first time, 15-9, 15-7. In the women's singles, Hong Kong's world number four Wang Chen looked every inch the Asian champion as she brushed aside Japan's Miho Tanaka for the loss of only two points. Wang was quickly turning her attention to fifth seed Camilla Martin of Denmark, talking of the '100 per cent fire' she had ready for an opponent who has beaten her three times in the past two months. However, the normally consistent Olympic silver medallist was ousted 11-5, 10-13, 11-4 by South Korea's world number 14 Jun Jae-youn. 'She didn't play so well. I don't think she had the right feeling in her body and that can influence your game,' said Martin's coach Kent Madsen. Martin's unexpected defeat provides Wang with a far more favourable match-up in this afternoon's quarter-finals, as Wang has won all six of her previous meetings with the Korean. 'We were quite surprised, we didn't expect Camilla to lose,'' said Chan Chi-choi. 'But you can't say it's good news until you've won the match.'