The former world number one looked extremely rusty and failed to get any momentum going throughout the match.
After dropping the first game, Wang tried to bounce back and force a decider, but Ongbumrungpan had other ideas and her her Chinese counterpart in 40 minutes.
Ongbumrungpan will now face Japan's Akane Yamaguchi in the semi-finals after she stunned number four seed Michelle Li of Canada 21-8, 15-21, 21-12.
Yamaguchi started off in dominant fashion and was on track to finish off Li in quick time, but the Canadian rallied back to clinch the second game and force a decider.
Determined not to be beaten, Yamaguchi recovered from her loss in the second game to win the decider and the match.
Meanwhile, it was smooth sailing for the men in their single's tournament as number one seed K. Srikanth cruised past number eight seed Takuma Ueda of Japan 21-11, 21-12.
Denmark's Viktor Axelsen had no problems in his match either as the number two seed made easy work of Hsu Jen Hao of Chinese Taipei, defeating him 21-13, 21-12.
In the men's doubles, Indonesia's Gideon Markus Fernaldi and Kevin Sanjaya Sukamuljo upset the Danish duo of Kim Astrup and Anders Skaarup Rasmussen 22-20, 19-21, 21-17 in a hard-fought battle.
There was also a major surprise in the women's doubles as the unseeded Japanese pair of Ayane Kurihara and Nari Shinoya beat number six seed Gabriela Stoeva and Stefani Stoeva of Bulgaria 21-14, 21-16 in 35 minutes.
It has also been confirmed that a new mixed doubles champion will be crowned this year after the reigning pair of Chris Adcock and Gabrielle Adcock were beaten by China's Lu Kai and Huang Yaqiong 23-21, 21-14.