Okuhara now faces her compatriot Ayumi Mine in the semifinals after Mine also caused an upset, toppling third-seeded Indonesian Millicent Wiranto in straight games, 21-18 21-13.
Second seed Chi Ya Cheng (Chinese Taipei) made quick work of her quarter-final and is now the only remaining seeded player in the draw, defeating countrywoman Pei Hsin Chiang 21-12, 21-16 in a business like performance. Cheng is yet to drop a game in the tournament and will approach the semi-finals fresh and full of confidence.
Men's top seed Hsu Jen Hao from Chinese Taipei was made to work hard for the second time in the day in taking his spot in the semifinals.
After young Kiwi Dylan Soedjasa pushed the athletic Hao in the morning, seventh seeded Chia-Hsin Wan (Chinese Taipei) took the second game in a tight tussle but eventually went down, Hao winning 21-19 18-21 21-13.
Indonesia's three-time Grand Prix winner, ninth seed Mohamad Arif Abdul Latif, among the more spectacular players at the event, continued his way through the draw, defeating Kuei Chun Shih (Chinese Taipei) 21-13, 21-17.
Fifth seed Arvind Bhat of India won the match of the night, beating third seed Chun Seang Tan of Malaysia 22-20 9-21 21-18.
"It feels great to be in the semifinals against Hao," Bhat said. "I lost against him last year but once I have beaten him, so let's take the positives and see how it goes."
Hosts New Zealand had its last players standing eliminated in the women's doubles quarter-finals last night.
Maria Mata Masinipeni and her Indonesian partner Wiranto lost to Australians He Tian Tang and Renuga Veeran 21-9 21-5; while Susanna Leydon-Davis and Kritteka Gregory also departed in a straight sets loss to a Chinese Taipei combination Szu Yu Chen and Cheng Chi Ya 21-14 21-16.