first-round bye. In the quarterfinals, she defeated 12th seed and defending champion Vera Zvonareva, to move through to her first semifinal at the tournament, where she lost to eventual champion Jelena Janković in straight sets, with Stosur making 47 unforced errors in the match. With her success, she reached a career-high ranking of No. 10, making her only the third Australian woman to achieve this feat in ten years, after Jelena Dokić reached No. 4 in 2002 and Alicia Molik reached No. 8 in 2005. In doubles, Stosur was third seed with Petrova. They had a comfortable route to the final, dropping only one set, where they lost to Květa Peschke and Katarina Srebotnik. Stosur's next tournament was the Miami Masters, where she was seeded ninth which allowed her a bye in the first round. She lost in the quarterfinals to eventual champion Kim Clijsters. In the doubles draw, Stosur and Petrova were seeded third and reached the final without dropping a set. However, Stosur and Petrova were defeated in the second straight final, losing in a super-tiebreak 7–10 to Gisela Dulko and Pennetta. Stosur began her clay-court season at the Charleston Open, where she was seeded fourth. In the final, she defeated Zvonareva in straight sets, for her fifth consecutive victory over the Russian. With this, she won her second and biggest WTA title, which put her back inside the top ten at world No. 10. She is the only Australian woman to have won this title. Stosur competed in the World Group Play-offs in Ukraine. After the first day, the Aussies had a commanding lead, going 2–0 against Ukraine. This was helped by a win from Stosur against Mariya Koryttseva, and Anastasia Rodionova's win over Alona Bondarenko. Stosur then secured victory for Australia with a two-sets win over Lyudmyla Kichenok. Because of this, Australia played in the World Group in 2011 against the top-seed Italy. Stosur then competed at the Porsche Grand Prix in Stuttgart. Her 11-game winning streak was ended by former world No. 1, Justine Henin, in the final in three sets. Despite this result, Stosur reached a new career-high ranking of world No. 8. Her next scheduled tournament was the Rome Masters; however, Stosur had to withdraw due to fatigue. With this, her next scheduled tournament was the Madrid Open. In the quarterfinals, Stosur was broken multiple times by Venus Williams, losing 3–6, 3–6. In