Tai Tzu-ying was on the end of a shock defeat at badminton’s World Championships on Friday, the number one from Taiwan going out in the quarter-finals to China’s He Bingjiao. It was just Tai’s second defeat in 35 matches, a run which brought five titles and cemented her status as the woman to beat in Nanjing. But the 24-year-old was sloppy at times, making a series of unforced errors, particularly at the net, and going down to the sixth seed over three unpredictable games. China’s He emerged after just under an hour to win 21-18, 7-21, 21-13 in a thrilling contest.