Unlike her tennis counterparts Steffi Graf and Martina Hingis, Anna Kournikova achieved international fame not for winning a championship tournament, but for the glamour and sex appeal she brought to the sport. The Russian-born beauty trained at an early age, displaying prowess on the court while training at top tennis academies. Kournikova captivated the sports world with an impressive Grand Slam debut at the 1996 U.S. Open, where she reached the fourth round of competition against top-ranked Graf. Kournikova failed to win a singles title throughout her career, but instead showed her strength as a doubles player along with her partner (and former competitor) Hingis. Trading in her tennis gear for skimpy swimsuits while posing in numerous magazine pictorials, including the 2004 Sports Illustrated swimsuit issue, helped rebrand Kournikova's image from a rising tennis star into one of the world's sexiest athletes. Despite attracting plenty of media attention for her bombshell court attire and her steamy romance with crooner Enrique Iglesias, Kournikova also used her fame to help others, whether it was playing in charity matches or appearing as a celebrity trainer on "The Biggest Loser" (NBC, 2004- ), which endeared her to millions as a genuine role model.