Andre Kirk Agassi ( AG-ə-see; born April 29, 1970) is an American former professional tennis player. He was ranked as the world No. 1 in men's singles by the Association of Tennis Professionals (ATP) for 101 weeks, including as the year-end No. 1 in 1999. Agassi won 60 ATP Tour-level singles titles, including eight majors, an Olympic gold medal, the 1990 ATP Tour World Championships, and 17 Masters titles, and he was part of the winning United States Davis Cup teams in 1990, 1992 and 1995. Agassi is one of nine men to complete the career Grand Slam in singles, and one of three men to complete the career Golden Slam in singles. A teenage phenomenon, Agassi contested multiple major finals before winning his first at the 1992 Wimbledon Championships. His ranking dropped afterward due to surgery, but he recovered and won the 1994 US Open and 1995 Australian Open to reach the world No. 1 ranking for the first time. He was then troubled by personal issues during the mid-to-late 1990s, and despite an Olympic gold medal at the 1996 Atlanta Olympics, Agassi's ranking declined to as low as No. 141 in 1997, prompting many to believe that his career among the elite was over. Following a rigorous training regimen, Agassi then enjoyed the most successful run of his career over the next several years. He returned to the world No. 1 position in 1999 after completing the career Golden Slam at the French Open, and during this latter half of his career also claimed a US Open title and three Australian Open titles. Competing well into the 2000s, Agassi retired from the sport following the 2006 US Open. Agassi is regarded by many as one of the greatest tennis players of all time. He was the first man to win all four singles majors across three different surfaces (hard, clay and grass), and remains the most recent American man to win the French Open (in 1999) and the Australian Open (in 2003). During his 20-plus year tour career, Agassi was known as "the Punisher" due to his excellent return of serve. Outside of tennis, he is the founder of the Andre Agassi Charitable Foundation, which has raised over $60 million for at-risk children in Southern Nevada. In 2001, the Foundation opened the Andre Agassi College Preparatory Academy in Las Vegas, a K–12 public charter school for at-risk children. He has been married to fellow tennis player Steffi Graf since 2001.