Despite Princess Diana standing only a few feet away, Cash yelled to his coach Ian Barclay: "We f---ing did it, Barkers, we  f---ing did it."

That unbridled emotion, which delayed the pomp and pageantry of the time-honoured trophy ceremony, was due to what Cash called his "rebellious streak", a trait that might be traced to his ancestor Martin Cash, an Irish convict transported to Van Diemen's Land in 1828 for shooting the man who embraced his mistress then found infamy as a bushranger after he escaped from Port Arthur.

Until his retirement in 1997, Cash was one of tennis's wild ones.

He wore a polished gold-cross earring, spoke his mind, played his tennis hard, played in a rock band and declared his three greatest treasures were guitars given to him by Tony Iommi of Black Sabbath, Judas Priest's Glenn Tipton and Mick Cocks from Rose Tattoo.

He paid a fortune for a pair of leather Versace pants covered in metal studs and, in his biography Uncovered, he confessed to bouts of rage, drinking to excess and drug abuse during his career.

Cash also revealed he struggled to overcome the fear of losing because it equated to humiliation and "no one loves a loser". In one episode, when he felt guilty about forfeiting a training session for a night on the town, he destroyed a hotel room in Adelaide.

Cash spoke on the phone in England while preparing to fly to Oslo to visit his daughter Mia and two grandchildren Talia and Patrick. He has four children: Daniel and Mia to Norwegian model Anne-Britt Kristiansen and twins Shannon and Jett to his former wife Emily Bendit.

He hoped the tennis lessons he put Mia through over Christmas wouldn't be as painful as their first one when she belted him over the head with her racquet. Cash heartily agreed he was too young to be a grandfather [four years ago] at 44, even though he was given the title "world's sexiest grandpop".

"It's a lot of fun," he said. "All the things they say about grandparents is true, you wind the kids up, have fun ... hand 'em back.

"Yeah, I thought I was too young to become  a grandfather and told my daughter that, but she didn't listen to me."

He also talked about playing in a Legends tournament – in the new Fast4 format – as part of next month's APIA International Sydney tournament, Twenty20 cricket, India and the tie to Australia that tugs at his heartstrings.

First it was tennis and playing before a home crowd that knew he revived the sport in Australia after the glory days of Lew Hoad, Ken Rosewall and John Newcombe had faded, and laid a foundation for Lleyton Hewitt, Pat Rafter and, hopefully, Nick Kyrgios and Bernard Tomic to gleam.

He scoffed at the notion of those old torments resurfacing when he plays alongside Henri Leconte against showmen Mansour Bahrami and Fabrice Santoro in the Legends matches.

"Competitive?" He laughed at the idea of climbing into the stands at the Sydney Olympic Park Tennis Centre on January 15 to embrace his supporters should he win his final doubles match during the APIA International Sydney.

"We're all at the half-century mark ... it's not too serious ...  it's about playing a good game, playing for fun. They're shorter, quicker matches under the Fast4 format and I think people will find them entertaining because the guys involved are all great players."

Cash, whose late father Patrick played for Hawthorn in the 1950s, bristled when it was suggested tennis might need something similar to cricket's Twenty20 format to engage Generation Next.

"Twenty20 is a bashathon," he said. "I love Test cricket. I understand the feel of it, it's enthralling. I've watched the highlights of the Australia-India series and kept an eye on Mitchell Johnson, who was a good tennis player, because I'm friends with his manager.

"Of all the sports, AFL is No.1 for me. Dad played for the Hawks and it was special to watch them go back-to-back [premiers]. I watched a bit of it this year."

Cash represented the Pune Marathas in the recent Indian Champions Tennis League alongside Marcos Baghdatis, Agnieszka Radwanska and local player Saketh Myneni in a tournament based on the Indian Premier T20 League.

"My body was feeling it," he said of the 10-day campaign. "[Pune] won the event, which made it even more enjoyable. I thought it was great to mix with the players of the modern era, the Venus Williams' of the world."

Cash said it was his mother Dorothy who made this hit-and-run mission to Australia tough.

"I'll play, I'll see friends in Sydney, I'll see the Australian Open, go to the Gold Coast and then head off [to work for CNN as host of Open Court] ... but I'll see my mum as much as I can," he said.

When it's suggested the things he said he missed about Australia would always be here, the wild one turned doting grandfather made an observation those of us who watched him during his prime could relate to.

"No, mate," he said with a surprising tenderness. "My mother ... it's really hard ... she's getting older."