was world No. 1, Wozniacki. Stosur continued her dominant showing, recording a straight-sets win to secure her spot in the semifinals. She then fell to Elena Dementieva, but secured her spot in the semifinals by winning one set. Stosur finished in first position in her round-robin group, but lost to three-time US Open champion and world No. 4, Clijsters, in the semifinals. Stosur ended her year ranked No. 6. In addition, she was the only player in 2010 to defeat both current world No. 1 players, Serena Williams and Wozniacki. She also had the best percentage of points scored on second serve amongst her peers. 2011: First major title at US Open and career-high ranking Stosur began the new season by competing at the Brisbane International. She fell in straight sets to fellow Australian Jarmila Groth in the second round. After this tournament, Stosur competed at the Sydney International as the fourth seed. She lost in the second round to Svetlana Kuznetsova. Stosur was seeded fifth at the Australian Open, where she lost in the third round to 25th seed Petra Kvitová. Stosur then rose to a new career high No. 4, following a quarterfinal showing at the Dubai Championships. She had a disappointing start to the first American leg of the year, falling in the third round of the Indian Wells to Dinara Safina. In Miami, she was seeded fourth, but was defeated in straight sets in the fourth round by 16th seed and former No. 1, Maria Sharapova. After Miami, Stosur played at Charleston, where she failed to defend her title, falling in the third round to Elena Vesnina in two sets. In Stuttgart, as fifth seed, Stosur lost to Julia Görges in the semifinals, but she won in the doubles tournament, partnering Sabine Lisicki, by defeating the German team of Kristina Barrois and Jasmin Wöhr in the final. Stosur's next tournament was the Madrid Open where she was the fifth seed. She lost in the third round to Anastasia Pavlyuchenkova in straight sets. She then competed in Rome where the sixth-seeded Stosur reached the final, but was beaten by seventh-seeded Sharapova. Stosur was seeded eighth at the French Open, yet was upset by Gisela Dulko, in the third round. As a result of this loss her ranking dropped to world No. 10. Stosur's next tournament was the Eastbourne International. She progressed to the semifinals, where she lost