All the big guns in action at the Japan on Tuesday made it safely to the second round – except for World No 1 Shi Yuqi.
Thai suttler Khosit Phetpradab claimed the first major scalp of the tournament as he eliminated the second seed from China 21-18, 24-22 in a huge shock result.
With Shi leading 13-12, Phetpradab went on a charge, winning six points in a row to take control of the first game. Shi rallied late, but his opponent held on to take the game.
Everyone expected a response from Shi, but instead it was Phetpradab who opened up a shock 12-4 lead at the start of the second game.
Shi fought hard and managed to get back on level terms at 20-all, but Phetpradab won the points that mattered at the death to seal a famous victory.
The other big guns had better luck, with top seed Viktor Axelsen, third seed Kento Momota and fourth seed Son Wan Ho all advancing safely.
Other winners included fifth seed Chou Tien Chen, sixth seed Chen Long and Kidambi Srikanth, the seventh seed from India.
Indonesia’s Anthony Ginting was responsible for knocking out another seed in Angus Ng Ka Long, the Hong Kung shuttler going down 21-14, 21-15.
There were no major upsets in the women’s draw, with World No 1 and top seed Tai Tzu Ying booking her place in the second round along with the likes of Akane Yamaguchi, P.V. Sindhu, Ratchanok Intanon and Chen Yufei.