2009 US Open – Women's Singles second round. This was also the final Grand Slam singles appearance of Ai Sugiyama, who was on a record-breaking 62nd consecutive Grand Slam singles appearance, lost in the first round to Samantha Stosur. Sugiyama's record-breaking run of 62 consecutive Grand Slam singles appearances remains unbeaten as of 2019. Dinara Safina "(Third round)" 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
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