Hong Kong teenager Casey Tse Ka-chun's first World Championships ended in heartbreaking fashion when the 17-year-old missed his final qualifying match. Tse, who was only entered in the men's singles, was due to face Russian Alexei Liventsov in the knockout round for a place in the main draw. However, Tse's coaches thought he had already earned his place among the big guns and were back at the team's hotel. Although the South China Morning Post raised the alarm, the disconsolate Tse arrived just moments after the match had been declared a walkover. 'There was nothing I could do. It was too late. I was pretty upset,' said the Hong Kong International School pupil. 'I didn't know I was going to play. It's a big lesson to learn from the World Championships.' Head coach Hui Jun, who together with his staff is responsible for managing the schedule, said: 'It is a great pity. We regret it very much. It was a very precious chance for him. He had played very well, especially in the second match, but now this has happened.' The mix-up occurred because of the confusing documentation of the tournament structure. While the qualifying groups and main draw were clearly laid out, the exact nature of how the 101 group winners would be whittled down to the 65 qualifiers had been difficult to ascertain. However, Tse was the only player to miss his tie. 'It happens sometimes, rarely, but this time it was not clear. Several other teams also complained about the way the knockout round was managed,' said Hui. 'We talked to the referee and the tournament organisers, but there is no way they could let him back in.' Tse refused to remain downcast, having beaten Tahiti's Jonathon Chewtchouk and Vietnam's Nguyen Nam Hai, who is rated more than 230 places above him, in his qualifying group. 'I don't feel sad anymore,' Tse said later. 'I feel I have made some real improvements from training with the Hong Kong squad. I had felt all right in my games and had played my own style. 'I want to learn as much as I can. I can watch the world-class players and see how they handle the ball, how they play, their technique. I've already seen so many things.' There was better news for Hong Kong in the mixed doubles, in particular the form of Song Ah-sim and Leung Chu-yan. The only Hong Kong pair to have to go through qualifying, Song and Leung shocked the Japanese Akira Kito and An Konishi - who had beaten Hong Kong's Asian Games gold medallists Tie Yana and Cheung Yuk at the Asian Championships - and then overcame French pair Agathe Costes and Christophe Legout to advance to the last 16. 'Our number one pair had lost to the Japanese, so we'd trained Song and Leung specially to meet them,' said Hui, a former world champion in the mixed doubles. Tie and Cheung also got through the first two rounds, as did all seven pairs from the mainland. The number one Hong Kong pair did so without losing a game against Belgian and Slovakian opposition. Tie, the world number seven, was equally as convincing in her opening singles against Chile's Sofija Tepes as all the Hong Kong women safely negotiated the first round. The two women's doubles pairs and their male counterparts also cleared the first hurdle.