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Tennis - Paris Masters tennis tournament men's singles quarterfinals - John Isner of the U.S. v Jack Sock of the U.S. - Paris, France - 4/11/2016 - Isner returns the ball. REUTERS/Gonzalo Fuentes Stock Photo - Alamy
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Novak Djokovic of Serbia returns the ball during the men's singles semifinal against Spain's Roberto Bautista at the Shanghai Masters tennis tournament in Shanghai, east China, Oct. 15, 2016. Novak Djokovic lost
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Monte Carlo, Monaco. 17th April, 2016. Rolex Monte Carlo Masters Tennis: Gael Monfils loses to Rafael Nada in the final of the Monte Carlo Masters title at the Monte-Carlo Country Club. Credit:
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