Samantha "Sam" Jane Stosur is an Australian professional tennis player. She defeated Serena Williams in the 2011 US Open finals to win her sole singles major title. Stosur is considered one of the most athletic and fittest players on the tour after battling Lyme Disease early in her tennis career. Her serves are widely known as the fastest shots in the women's game, while her favorite surface is likely the hard court. Stosur has been to three Summer Olympics, taking place in Beijing, Athens, and London.