China's Peng Shuai celebrates after defeating Venus Williams of the US. [Photo/Agencies]

BEIJING - The first major upset of the tournament was produced on Monday by Chinese wild card Peng Shuai, who defeated 6th seed Venus Williams of the United States 7-5, 6-1 in the first round of the China Open.

Peng proved a tenacious opponent for the elder Williams sister from the outset of the match, and needed just one hour 26 minutes to send Venus packing.

The first set was hotly contested but Peng showed her battling qualities at big moments, breaking her opponent twice to take the opening set.