NEW YORK, NY - SEPTEMBER 03: Caroline Wozniacki of Denmark reacts against Petra Cetkovska of the Czech Republic during their Women's Singles Second Round match on Day Four of the 2015 US Open at the USTA Billie Jean King National Tennis Center on September 3, 2015 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Clive Brunskill/Getty Images)
