Serbia's Novak Djokovic gestures as he waits for a serve during an exhibition charity match with China's Li Na (not pictured) to mark the opening of 2013 China Open Tennis Tournament, in Beijing, ... more 
Serbia's Novak Djokovic gestures as he waits for a serve during an exhibition charity match with China's Li Na (not pictured) to mark the opening of 2013 China Open Tennis Tournament, in Beijing, September 27, 2013. This year marks the 10th anniversary of the China Open. REUTERS/Barry Huang (CHINA - Tags: SPORT TENNIS) less 
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Reuters | Photo By BARRY HUANG / REUTERS
Fri, Sep 27, 2013 10:21 AM EDT