NEW YORK, NY - SEPTEMBER 11:  Flavia Pennetta of Italy celebrates after defeating Simona Halep of Romania in their Woman's Singles Semifinals match on Day Twelve of the 2015 U.S. Open at the USTA Billie Jean King National Tennis Center on September 11, 2015 in the Flushing neighborhood of the Queens borough of New York City.  (Photo by Mike Stobe/Getty Images for the USTA)