2016 U.S. Open - Day 11  Serena Williams of the United States reacts during her loss against Karolina Pliskova of the Czech Republic in the Women's Singles Semifinal match on Arthur Ashe Stadium on day eleven of the 2016 US Open Tennis Tournament at the USTA Billie Jean King National Tennis Center on September 8, 2016 in Flushing, Queens, New York City.  (Photo by Tim Clayton/Corbis via Getty Images)
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