Upon winning the 1987 singles title at Wimbledon, Cash climbed into the stands to celebrate, starting a tradition that has continued ever since.

In June 1982, Cash won the junior doubles title at the French Open partnering John Frawley.

Cash turned professional in late 1982 and won his first top-level singles title that year in Melbourne.

He won the decisive singles rubber against Joakim Nyström as Australia defeated Sweden 3–2 to claim the cup.

He reached the quarterfinals, playing "breath-taking tennis" to beat Mats Wilander in the fourth round in only his sixth match (excluding 1986 World Team Cup) in 12 months.

Having already beaten Marcel Freeman, Paul McNamee, Michiel Schapers, Guy Forget, Mats Wilander in the quarterfinals and Jimmy Connors in the semifinals, Cash defeated the world No.

Cash sealed the victory by climbing into the stands and up to the player's box at Centre Court, where he celebrated with his family, girlfriend, and coach, Ian Barclay.

In 1988, Cash reached the Australian Open final for the second consecutive year, beating Ivan Lendl in five sets in the semis, as Lendl struggled in the latter stages due to heat and Cash repeated his tactics of the 1987 Wimbledon final.

It was the first men's singles final played at the new Melbourne Park venue on hard court, and Wilander won in a four-and-a-half-hour encounter, taking the fifth set 8–6.

It was the first men's Grand Slam final in history to be played indoors after rain delays forced the closing of the roof midway through the match.

A series of consecutive injuries to his Achilles tendon, knees, and back prevented him from recapturing his best form after winning Wimbledon in 1987.

Cash established a reputation on the tour as a hard-fighting serve-and-volleyer and for wearing his trademark black-and-white checked headband and his cross earring.

He is the host of CNN's tennis-focused magazine show Open Court,[16] and has also worked as a TV co-commentator, primarily for the BBC.

[19] Cash was criticised for stating in an August 2021 interview with The Conservative Woman, broadcast online, that he had been taking Ivermectin for more than 15 months, claiming that "I'm living proof that I have been in the worst areas everywhere around the world and I haven't come close to getting COVID", despite the lack of evidence for the safety or efficacy of the drug for such measures.

[20][21][22] Cash and former American surfer Kelly Slater were labelled "cookers" (conspiracy theorists) after they exchanged views on Twitter about the concept of the 15-minute city in February 2023.