World No 3 Ratchanok Intanon has been knocked out of the Yonex All England Open, losing a tough first-round match 15-21 21-14 19-21 to the Canadian Michelle Li in Birmingham, England.
The Thai No 1, a finalist last year, had never lost to the world No 17 in four previous meetings.
This was also a great shock for Ratchanok, the former world champion, who won her first tournament of 2018 in Malaysia and reached back-to-back semi-finals at the Indonesia Masters and India Open.
“I felt a bit excited to be playing the first match of the day but I could not play my normal game and made many errors. My opponent was very solid in her defence,” she said.
“I have to apologise to all my fans for letting them down.”
Former world top-10 player Tanongsak Saensomboonsuk also crashed out, losing her first-round match 17-21 18-21 to Wang Tzu Wei of Taiwan.