Sharapova participated in the first Grand Slam of the season at the Australian Open, where she was the 14th seed, but lost to Andrea Petkovic in the fourth round.  She also had to pull out of the 2011 Dubai Tennis Championships and 2011 Qatar Ladies Open because of an ear infection.  Sharapova returned to the tour in March by taking part in the 2011 BNP Paribas Open, where she was seeded 16th. She defeated former world No. 1 Dinara Safina, in the fourth round en route to the semifinal, where she lost to world No. 1 Caroline Wozniacki.  At the 2011 Sony Ericsson Open in Key Biscayne, Sharapova defeated 26th seed Alexandra Dulgheru in the quarterfinals, in a match lasting 3 hours and 28 minutes.  In the semifinals, Sharapova took her Australian Open reprisal on Germany's Andrea Petkovic by defeating her. In the final, she was defeated by Victoria Azarenka, despite a late comeback in the second set.  With this result, Sharapova returned to the top 10 for the first time since February 2009.