NEW YORK, NY - SEPTEMBER 10:  Karolina Pliskova of the Czech Republic returns a shot while playing against Angelique Kerber of Germany during their Women's Singles Final Match on Day Thirteen of the 2016 US Open at the USTA Billie Jean King National Tennis Center on September 10, 2016 in the Flushing neighborhood of the Queens borough of New York City.  (Photo by Michael Reaves/Getty Images)