NANJING, Aug. 3 (Xinhua) -- Top seed Tai Tzu Ying of Chinese Taipei failed to clinch her first Badminton World Championship medal as she crashed out of the women's singles quarterfinals to China's He Bingjiao 21-18, 7-21, 21-13 here on Friday.

With five titles from six events this year, Tai headed into the World Championships as the overwhelming favourite. However He, world no. 7, had a better start by narrowly taking the first set 21-18. In the second set, Tai appeared to have things under control with an 8-0 lead and eventually leveled the match by winning the set 21-7.

But Tai fell apart again in the decisive set as He maintained the lead from the early start and cruised to victory, the biggest upset at this year's tournament so far.

"Today I made several mistakes in the third set, and also had some simple faults in the opening set," admitted Tai. It's only the second loss for Tai this year in 36 matches.

She kept a six straight win record against He before this match. "We are familiar with each other's playing style. Today her drop points were always tricky, making it difficult for me to control the mistakes," added Tai.

Tai has won nearly every major world tour title, but she hasn't quite delivered at the World Championships and the Olympics.

"For me (the winning streak and world ranking) is pressure. Although I thought I was enjoying the match, I made too many mistakes and [became] frustrated," she said.

The Chinese player had only won once in her seven encounters against Tai before this match.

"I felt great after beating Tai as she is my biggest opponent. I had never imagined I can enter the top four, but I finally did it. I can't relax now as I have to prepare for the next match," said He.

He will face Carolina Marin in the semifinals after the Spaniard took an easy victory against India's Saina Nehwal 21-6, 21-11.