12. Despite being the favourite to win the Mercury Insurance Open, Azarenka withdrew to recover from a right shoulder injury. Seeded ninth at the Western & Southern Open, Azarenka was stunned in the first round by world No. 62, Ana Ivanovic, despite serving for the match twice in the second set, and being within two points of victory on Ivanovic's serve; it was Azarenka's second defeat by Ivanovic in 2010. However, she won the doubles title, partnering with Maria Kirilenko, defeating Lisa Raymond and Rennae Stubbs. 1 September 2010, daytime, at the US Open, losing 0–4 during her second round against Gisela Dulko, Azarenka collapsed on the court. There were concerns that the cause of the fall was heat-related. Azarenka was taken to a local hospital for treatment and was diagnosed with a concussion after hitting her head whilst warming up before the match during a sprint exercise. Azarenka won only seven Grand Slam matches for the entire year, matching her 2007 tally. At the Pan Pacific Open, she lost to Caroline Wozniacki in the semifinals in three sets. Azarenka re-entered the top 10 after this run. At the China Open, Azarenka retired in her second-round match to Timea Bacsinszky. At the Kremlin Cup Azarenka, as the second seed, defeated Maria Kirilenko in the final, coming back from 4–0 down in the second set to win her fifth career title. Azarenka's performance in Moscow qualified her for the year-end Tour Championships, where she was in the White Group as the eighth seed. In her first round-robin match, Azarenka lost to Vera Zvonareva, and then lost to Kim Clijsters in her second match. This assured that she did not qualify for the semifinals. In her final match of the tournament and season, she defeated Janković for the second year in a row. Azarenka ended the year as world No. 10, her second consecutive year-end top-10 finish. 2011: Miami Open title, WTA Tour Championships final Azarenka began her year at the Medibank International as the seventh seed, where she lost to Kim Clijsters in the quarterfinals. At the 2011 Australian Open Azarenka was seeded eighth. She lost to the ninth seed and eventual finalist, Li Na in the fourth round. Azarenka partnered with Maria Kirilenko in the women's doubles event, but the pair lost to Gisela Dulko and Flavia Pennetta in the final. Azarenka then travelled to Israel to compete in Fed