Maria Sharapova won Wimbledon at just 17 years old, in an astonishing upset against the reigning champion Serena Williams --- the match that kicked off their legendary rivalry and placed Sharapova on the international stage. At 18, she reached the number one WTA ranking for the first time, and has held that ranking many times since. In UNSTOPPABLE, the five-time Grand Slam winner recounts the story of her phenomenal rise to success, narrated with the same no-holds-barred, fiercely provocative attitude that characterizes her tennis game.