China's Zhao Junpeng shocked world silver medalist Kidambi Srikanth of India 21-9, 21-17 to reach the men's singles third round at the World Badminton Championships on Wednesday.
Zhao, ranked 23rd in the world, needed only 34 minutes to beat 12th seeded Srikanth, the defeated finalist in last year's World Championships in Huelva, Spain.
Zhao, a beaten quarterfinalist last year in Huelva, next plays fifth seed Lee Zii Jia of Malaysia.
"I've played with him earlier this year. I was not that confident at that time. So tomorrow I will try my best," said Zhao.
In the women's singles, fourth-seeded Chen Yufei of China also advanced easily.
The reigning women's doubles pair Chen Qingchen and Jia Yifan of China stormed to the last 16 after beating Indian pair Ashwini Ponnappa and Reddy N. Sikki 21-15, 21-10.
Elsewhere, top-seeded men's doubles pair Marcus Fernaldi Gideon and Kevin Sanjaya Sukamuljo from Indonesia advanced into the round of 16. In the past five years, they have never won a World Championships or Olympic medal.
"Of course, we want to be champions here. We will just keep focused, take it step by step and try our best. We don't want to have any extra pressure," said Sukamuljo.