KEY POINTS:
In one corner is a clean-cut family man who is the undisputed king of New Zealand ironman, going for his seventh straight title next weekend.
In the other is a dreadlocked upstart who has had run-ins with the establishment and who desperately wants to dethrone the monarch.
It's fair to say Cameron Brown and Kieran Doe couldn't be more different. They are like chalk and cheese, Dr Jekyll and Mr Hyde, Diana and Camilla. As in the relationship between the women in Prince Charles' life, there's also an underlying tension.
"We say 'hi' and 'bye' to each other and that's about it," Brown says, even though they're in the same swim squad with former national coach Mark Bone. "There's no real friendship there. We are totally different."
It's hard to imagine Brown, who has children aged six and four, giving Triathlon New Zealand selectors the one-fingered salute as Doe did as he crossed the line to win his age group section at the 2003 short-course world championships in Queenstown after he missed out on the elite squad.
"It was a signal that said No 1," Doe says with a sheepish grin.
It's also hard to imagine Brown turning up for a training run barefoot, or with dreadlocks, pink belts, trucker hats or listening to dance music on the long, lonely roads of the Waitakeres on a training ride.
Doe acknowledges he's different but thinks people misinterpret him.
"I was a bit of a troubled kid," he explains. "I had ADHD in my teens so had lots of energy to burn and that seemed to get me into trouble.
"But I think people view me the wrong way. A lot initially thought I was arrogant when I'm actually quite shy. When I first came up [to Auckland from Feilding seven years ago] I didn't really say a lot. I had a bit of a walk, a strut. I've got my own style about me and I think people took it the wrong way.
"I don't see myself as arrogant. I'm confident but you need to be to be the best and to keep getting better. Cameron Brown was one who took it the wrong way. I came out a couple of years ago and beat him at the half [ironman in Tauranga] and he didn't like that. I talked in the papers and he took it the wrong way.
"There's no other athlete in New Zealand I respect more than Cameron. He's a machine. He's incredible. But come race day I want to beat him. And why wouldn't you?"
Come Saturday, Doe thinks he is a genuine threat to Brown's dominance of a race that stretches back to 2001 (Brown was second in 2006 when bad weather cancelled the swim leg.) He will go out hard in the 3.8km swim and the 180km bike and then hope he has a big enough lead heading into the 42.2km run.
Doe won the last time they met, at January's Port of Tauranga Half Ironman, and at last year's Ironman Canada. He warmed up with an easy win at yesterday's short-course event in Napier.
Many believe he is the future of New Zealand ironman, particularly as he is only 26. Brown, though, is undoubtedly the present.
A win in Taupo would be a world record seventh-straight victory for the 35-year-old and he rates Doe as only one of a number of threats that include Australians Luke Bell and Peter Jacobs.
There will also be plenty of interest in the performance of Richard Ussher, the three-time Coast to Coast winner who is racing in his first ironman, as well as women's favourite Jo Lawn.
Like Brown, the 34-year-old Lawn is chasing what would be an incredible sixth-straight ironman victory, a record in women's ironman history.
The former Commonwealth Games cyclist's greatest threats will come from Christchurch's Gina Ferguson, Scotland's Bella Comerford and Australian Kate Bevilaqua.
