NEW YORK, NY - SEPTEMBER 05: Kei Nishikori of Japan shakes hands after defeating Ivo Karlovic of Croatia during his fourth round Men's Singles match on Day Eight of the 2016 US Open at the USTA Billie Jean King National Tennis Center on September 5, 2016 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Michael Reaves/Getty Images)
