When Agassi was 13, his father sent him to the notoriously tough Nick Bollettieri Tennis Academy in Bradenton, Florida, where the country's top young tennis players attended classes and practiced tennis for five hours a day. Future champions Jim Courier and Monica Seles also trained with Bollettieri during their early careers, but Agassi was the flamboyant coach's prize pupil. Agassi spent three years at the academy and won a total of five United States Tennis Association (USTA) national junior titles before turning pro on May 1, 1986, just two days after his 16th birthday.

With his fierce two-handed backhand and volatile backcourt game, Agassi was one of the most highly touted newcomers on the professional tennis scene. He won his first tournament in 1987 and rose from No. 41 to No. 24 in the world rankings. In 1988, he won six tournaments, reached the semifinals of two Grand Slam events, the French Open and the U.S. Open, and rose to No. 3 in the world at the age of 18.

Beyond his powerful tennis, Agassi earned even more publicity for his outlandish personal style long, blond-streaked hair, unshaven face, pierced ear, and garishly colored clothing that stood out against the background of the traditionally conservative sport. His playful on-court style also endeared him to fans, especially his trademark habit of applauding an opponent's winning shot by clapping his hand against his racket. With high-profile (and lucrative) endorsement contracts with Nike (sportswear), Dunlop (tennis rackets), and Canon (cameras), Agassi was probably the most visible tennis player in the world, even without a major title.