Serena Williams (left) of the United States greets Kiki Bertens of the Netherlands after defeating her to win their Women’s Singles Second Round match on Day Three of the 2015 US Open at the USTA Billie Jean King National Tennis Center on Thursday in the Flushing neighborhood of the Queens borough of New York City. AFP PHOTO
NEW YORK: Serena Williams struggled but advanced toward the first calendar Grand Slam since 1988 by defeating Dutch qualifier Kiki Bertens 7-6 (7/5), 6-3, on Wednesday (Thursday in Manila) at the US Open.