The unseeded Thai player recorded a shock 21-18, 24-22 victory over Shi at the Musashino Forest Sports Plaza in Tokyo, a venue due to be used when the Japanese capital hosts the 2020 Olympic and Paralympic Games.

Dutchman Mark Caljouw, a 21-14, 21-17 winner in his match against Chinese Taipei's Wang Tzu Wei, awaits for Phetpradab in round two.

Reigning Olympic champion Chen Long of China fought back from a game down to beat Indonesia's Tommy Sugiarto 12-21, 21-17, 21-14.

Chen will take on Thailand's Suppanyu Avihingsanon in the next round.

Japan's newly-crowned world champion Kento Momota also progressed as he comfortably overcame Denmark's Anders Antonsen 21-9, 21-10.

Top seed and Olympic bronze medallist Viktor Axelsen of Denmark made light work of Chinese Taipei’s Hsu Jen Hao with a straightforward 21-12, 21-9 win.

In the women's draw, American Beiwen Zhang and Michelle Li of Canada were among the high-profile first-round casualties.

Zhang was beaten 21-13 21-12 by Chinese youngster Chen Xiaoxin in just 36 minutes, while 2014 Commonwealth Games champion Li lost 21-11, 21-14 to Chen's team-mate Cai Yanyan.

Thailand's Ratchanok Intanon survived a scare, dropping the opening game before coming through with a 17-21, 21-9, 21-15 win over home player and recent US Open champion Minatsu Mitani.

Spain's Carolina Marin, the reigning Olympic and world champion, booked her place in the second round by easing to a 21-7, 21-12 victory over Japan's Saena Kawakami.