Agassi's willingness to test the limits of a traditionally conservative sport immediately got the sponsors interested, but his appeal didn't diminish as he grew older (and his hair got thinner).

At 34, he reportedly earned �15m in sponsorship and it is estimated that over 20 years he has earned more than �100m alone from endorsement deals, comparable with Tiger Woods, Michael Jordan and David Beckham.

Agassi established a charitable foundation in 1994 through which he has raised more than �30m. Five years ago, he opened the Andre Agassi College Preparatory Academy, a school for at-risk children in Las Vegas.