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
2010 US Open – Men's Singles grass in the same calendar year. 2010 US Open – Men's Singles Juan Martín del Potro was the defending champion, but chose not to participate this year, after undergoing a wrist operation in May and only starting to practice again in August. Del Potro was the third man in the Open Era not to defend his US Open title, after Ken Rosewall in 1971 (due to conflicts between the World Championship Tennis (WCT) and the International Lawn Tennis Federation (ILTF)), and Pete Sampras in 2003 (who unofficially retired after the 2002 final). For the first time in U.S. Open history,