Rafael Nadal announced his retirement from tennis on Thursday, signaling the end to a career that spanned two decades and 22 Grand Slam titles, including 14 on his favorite clay at Roland Garros, and 92 singles titles overall. Reached third round in Wimbledon debut at 17, youngest man to get that far at the All England Club since Boris Becker was 16 in 1984. Beat then-No. 1 Roger Federer in Miami.