Malaysia's Wong Choong Hann effectively ended the Olympic career of Athens gold medallist Taufik Hidayat of Indonesia when he beat him 21-19 21-16 in the men's singles round of 32 on Monday.
In another upset, unseeded Japanese badminton duo Miyuki Maeda and Satoko Suetsuna pulled off "the win of their lives" to eliminate Olympic champions Yang Wei and Zhang Jiewen in the women's doubles.
Later, China's second seeds Du Jing and Yu Yang crushed Kimuko Ogura and Reiko Shiota of Japan 21-8 21-5 in what the predominantly Chinese crowd clearly considered a revenge match, screaming "Kill!" in unison with each Chinese shot.
Taufik, who celebrated his 27th birthday on Sunday with cake and more practice, suffered a bout of Dengue Fever ahead of the Games and was released from hospital just two weeks ago.