NEW YORK, NY - SEPTEMBER 06: Novak Djokovic of Serbia serves to Jo-Wilfried Tsonga of France during their Men's Singles Quarterfinals match on Day Nine of the 2016 US Open at the USTA Billie Jean King National Tennis Center on September 6, 2016 in the Queens borough of New York City. (Photo by Chris Trotman/Getty Images for USTA)
