China's world No 1 Wang Shixian hits a return against Inthanon Ratchanok of Thailand in the women's singles second round of the China Open in Shanghai, Nov 24, 2011. [Photo/CFP]

World No 1 Wang Shixian of China burst into tears after being stunned by Thai teenager Inthanon Ratchanok in the women's singles second round of the China Open on Thursday.

Wang, last year's BWF (World Badminton Federation) Superseries Finals champion, blamed her lack of patience for the 18-21, 19-21 defeat at the young Thai's hands.

"I was too impatient on the court today, which led to numerous faults," said Wang, who turned around to wipe tears off her face before being interviewed.

Wang has struggled with her game in recent tournaments. I really hope that I can find a way-out as soon as possible," she said. "I need to improve both techniques and mindset."

Thai teenager player Inthanon Ratchanok (L）reacts after beating China's world No 1 Wang Shixian (R) in the women's singles second round of the China Open in Shanghai, Nov 24, 2011. [Photo/CFP]

Meanwhile, Inthanon Ratchanok, who earned her fame as the youngest-ever world junior champion when she won the BWF World Junior Championship title at the age of 14, was elated about her victory.

"I'm very happy because I can beat the No 1 right now. I feel more confident about myself because if this time I can beat China, then I can try to achieve more in the future," the 16-year-old Ratchanok said through an interpreter.

Record-breaking floods have inundated vast areas of Thailand over the past several months. Ratchanok said her home is also in the flood-affected zone.

"I hope my family back in Thailand are happy about my victory," said Ratchanok.