Olympic champion Li Xuerui of China failed to give one significant honor missing from her ever-expanding trophy cabinet as she was defeated by Thailand's 18-year-old Ratchanok Intanon 22-20, 18-21, 21-14 in the women's singles final.

Li squandered a 19-12 lead in the opening set as the hope of Thailand stormed back to take it by scoring five points in a row after trailing 20-17.

The second set was still a neck-and-neck contest, in which both sides traded point by point until 15-all. A smash into the net from Ratchanok gave Li the set.

However, Ratchanok regrouped herself in the decider, surging to an 8-2 lead and playing confidently to eventually secure the victory.

Beating the top shuttler from powerhouses China, Ratchanok hoped that could help Thai badminton develop.

"This victory increased my confidence and my next aim is the Olympic gold medal." she said.

"This is my first world championships. When I was close to the title, my mind went something wrong," commented Li, the No 1 seed of the event.

In the women's doubles, China's Yu Yang/Wang Xiaoli, who were disqualified for match-throwing from the Olympic Games in London, proved themselves by beating eighth seed Eom Hye Won/Jang Ye Na of South Korea 21-14, 18-21, 21-8.

Indonesia won the men's doubles and mixed doubles as Mohammad Ahsan/Hendra Setiawan beat Mathias Boe/Carsten Mogensen of Denmark 21-13, 23-21, while Tontowi Ahmad/Liliyana Natsir outclassed top seed Xu Chen/ Ma Jin of China 21-13, 16-21, 22-20 in the mixed.