NEW YORK, NY - SEPTEMBER 09: Stan Wawrinka of Switzerland reacts to winning the second set against Kei Nishikori of Japan during their Men's Singles Semifinal Match on Day Twelve of the 2016 US Open at the USTA Billie Jean King National Tennis Center on September 9, 2016 in the Queens borough of New York City. (Photo by Chris Trotman/Getty Images for USTA)
