Novak Djokovic of Serbia hits a return shot to Marin Cilic of Croatia during their quarter final round match in the Cincinnati Open tennis tournament in Cincinnati, Ohio, August 17, 2012. (Xinhua/Reuters Photo)
Novak Djokovic of Serbia hits a return shot to Marin Cilic of Croatia during their quarter final round match in the Cincinnati Open tennis tournament in Cincinnati, Ohio, August 17, 2012. (Xinhua/Reuters Photo)