NEW YORK, NY - AUGUST 26:  Ana Ivanovic of Serbia reacts against Alison Riske of the United States during her women's singles first round match on Day Two of the 2014 US Open at the USTA Billie Jean King National Tennis Center on August 26, 2014  in the Flushing neighborhood of the Queens borough of New York City.  (Photo by Elsa/Getty Images)