2017 U.S. Open Tennis Tournament - DAY EIGHT. Juan Martin del Potro of Argentina during his five set win over Dominic Thiem of Austria in the Men's Singles round four match at the US Open Tennis Tournament at the USTA Billie Jean King National Tennis Center on September 04, 2017 in Flushing, Queens, New York City.  (Photo by Tim Clayton/Corbis via Getty Images)