Feng, seeded third, was pushed to five full games before overcoming her 15-year-old opponent, 8-11, 11-8, 11-6, 9-11, 11-6.

Ito had been looking to continue the superb form that saw her beat Chinese world champion Ding Ning at the Asian Olympic Qualification Tournament in Hong Kong earlier this month.

"Mima attacks really fast from the backhand, so for me it was important that when she played to my backhand I focused on being consistent, putting the ball back on the table," said Feng.

"From the forehand I played with as much spin as possible; not too fast."

India's Manka Batra was among other unbeaten players on a day of group stage action, along with Chinese duo Liu Shiwen and Li Xiaoxia.

There was also success for China in the men's draw as top seed Xin Xu easer through his group with victories over South Korea's Jung Joungsik and Taiwan's Chiang Hung-chieh.

He also secured a walkover over the injured Yuya Oshima of Japan.

Xu's compariot Zhang Jike was similarly successful in completing an unbeaten opening day with three 3-0 victories over Hong Kong's Wong Chun Ting, South Korea's Lee Sangsu and India's Sharath Kamal Achanta.

Japan’s Jun Mizutani, the number four seed, was similarly successful with 3-1 wins over Taiwan's Chuang Chih-Yuan and Hong Kong's Ho Kwan Kit and a 3-0 triumph over Singapore's Gao Ning.