'He's a great guy': Serena Williams and Dustin Martin in Melbourne meet-up
One has 23 major titles, a baby and boasts her own line of "strong, sexy and sophisticated" clothing.
The other has two AFL flags, neck tattoos and counts Sam Newman as a friend.
But Serena Williams and Dustin Martin will renew their unlikely friendship this month in Melbourne alongside this month's Australian Open having forged a bond while holidaying in the Maldives last year.
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Williams revealed the meeting of tennis and Australian Rules' finest on her Instagram account in November.
Martin was pictured sipping drinks while Williams' partner Alexis Ohanian played music at an exclusive poolside resort in Williams' Instagram story.
Until now, disbelieving Australians among Williams' near 12 million Instagram followers were left none the wiser as to their friendship.
On Friday, after dispatching Germany's Laura Siegemund to reach the semi-finals of Auckland's ASB Classic, Williams revealed the friendship blossomed after an introduction.
"He's friends with one of my best friends and they were there and he was there," Williams explained.
"He's super athletic. We did some watersport and he killed me in it. I was like 'ahh - I'm not even gonna try. This is my off season!'
"He's a great guy. I loved hanging out with him."
Williams has maintained contact, saying, "We definitely plan on catching up".
Their budding friendship means loyalties at Richmond's Punt Road base, just across from Melbourne Park, will be mixed during the 2020 tournament.
Ashleigh Barty, the world No.1, is a huge Richmond fan and has regularly hosted Tigers captain Trent Cotchin in her box during her matches in Melbourne.
The meeting of Barty, the Australian favourite, and Williams, the history-chasing legend, would be a dream final on Saturday February 1.
Serena heartbroken over bushfire crisis
And while the pair will be rivals on the court, both have helped raise funds to help those affected by bushfires in Australia.
Barty pledged her winnings of US22,050 (A$32,129) from the Brisbane International, while Williams has provided a match-worn dress from her run in Auckland, as well as a tennis ball signed with doubles partner Caroline Wozniacki, for auction.
"It's just tragic," Williams said of the vast bushfires.
"I don't even like talking about it."
"My love for animals and my love for people ... I'm asking, 'What can I do to help?', because I want to be able to help.
"I've been coming for Australia for over 20 years. I think '98 was my first year. It is a place I've won so many grand slams at. Singles, doubles.
"It's one of my favourite places to come.
"It's one of the only places where if I lose, you will still see me around."
