Maria Sharapova
It’s hard to believe Maria Sharapova turned pro in 2001 and turns only 21-years-old in 2008. The three-time Grand Slam tournament champion won the Australian Open in 2008 and now must capture the French Open title to have won all four Grand Slam tournaments. Incredibly, her first Grand Slam singles title came when she was just 17, defeating Serena Williams in the U.S. Open in 2004. With many years ahead of her, only time will tell how many titles this future legend will capture. (Credit: AP)