Chinese teenager Guo Yue became the youngest ever winner of a Pro Tour singles title when she defeated fellow-mainlander Guo Yan in the final of the Japan Open in Kobe. The 15-year-old cruised to a comfortable 11-9, 11-7, 12-10 11-5 victory having defeated her doubles partner Niu Jianfeng, earlier in the day. 'This is a very big surprise for me. Guo Yan was the big favourite so I am extremely happy I could beat her in four straight games,' said a delighted Guo Yue, who also combined with Niu to win the doubles, heaping further misery on Guo Yan and her partner Li Nan with a 11-8, 11-5, 9-11, 11-9, 11-7 victory, to add to the Korean Open title they won three weeks ago. 'Guo Yue's game is very fast, she is talented,' said Lu Yuansheng, the women's national coach. In the men's competitions, Ma Lin failed in his bid to win six titles in the space of three weeks when he was beaten by South Korea's Oh Sang-eun in the semi-finals of the singles. The title went to the world number one Timo Boll of Germany who beat Oh 4-2 in the final, having accounted for Wang Liqin in the previous round. However Ma did win his third consecutive doubles title with another teenager Chen Qi defeating Wang and Hao Shuai 11-9, 11-9, 7-11, 11-8, 8-11, 3-11, 11-7.