2009 US Open – Women's Singles 2009 US Open – Women's Singles Serena Williams was the defending champion, but was defeated in the semifinals by the eventual champion Kim Clijsters. Clijsters defeated first time Grand Slam finalist Caroline Wozniacki in the final to win her second US Open title. Clijsters became the first unseeded player and wild card to win the tournament, and the first mother to win a major since Evonne Goolagong in 1980. Following her win, she made 19th in the rankings. This was the final Grand Slam appearance for former two-time Grand Slam champion, Amélie Mauresmo, who lost to Aleksandra Wozniak in the
US Open (tennis) the 1968 national tournament were open to professionals. That year, 96 men and 63 women entered, and prize money totaled US$100,000. In 1970, the US Open became the first Grand Slam tournament to use a tiebreaker to decide a set that reached a 6–6 score in games. From 1970 through 1974, the US Open used a best-of-nine-point sudden-death tiebreaker before moving to the International Tennis Federation's (ITF) best-of-twelve points system. In 1973, the US Open became the first Grand Slam tournament to award equal prize money to men and women, with that year's singles champions,John Newcombe and Margaret Court, receiving