Serena Williams on the brink of history

Two matches from making history. That's the position Serena Williams finds herself in going into her U.S. Open semifinal against Roberta Vinci. Should two positive results follow in New York over the coming days then she will have achieved something only ever done before in the women's game by three others -- the calendar grand slam. No female player since Steffi Graf in 1988 in the Open Era has managed the feat, while Maureen Connolly and Margaret Court are the only others to find themselves on such an esteemed list, securing their slams in 1953 and 1970 respectively. No male, meanwhile, has done it since Rod Laver in 1969. But with the Australian Open, French Open and Wimbledon titles already in the bag this year, Williams has the chance to rewrite the record books at Flushing Meadows. She has already claimed the so-called "Serena Slam" -- for the second time in her career -- having won the last four majors in a row, and is now on course for one of the greatest runs ever in professional tennis. World No. 43 Vinci stands in her way, before a potential final against Flavia Pennetta or second seed Simona Halep, should Williams safely negotiate her way past the Italian. Williams and Vinci were due to battle Thursday but rain pushed back the women's semifinals to Friday. Vinci, who is competing in her first ever grand slam semifinal after beating Kristina Mladenovic in three sets in the previous round, has not beaten Wiliams in four career attempts.