Cameron Brown has dominated the Ironman New Zealand event in Taupo for 10 years.
But he will face his toughest test yet at this year's race on March 3, with confirmation the fastest ironman on the planet will be against him.
Belgium's Marino Vanhoenacker set the triathlon world in a spin last year when he set a new world record ironman time of 7:45.50 in Austria - taking five minutes off the previous best established 14 years earlier.
The 35-year-old is a six-time winner of Ironman Austria and a podium placegetter at the ironman world championships in Hawaii.
Vanhoenacker says it will be daunting taking on Brown, who last year became the first person in triathlon history to win the same ironman 10 times with his victory at Taupo.
"I am not sure how big my chances are to beat him or get close to him but I sure hope I can make him sweat a little bit at least," Vanhoenacker said. "He kills everyone who turns up. It is his race. He owns the race. I hope I can be some competition for Mr Ironman New Zealand."
The Belgium athlete likes to race early in the year, having previously won in South Africa and Malaysia during the northern hemisphere winter months. His decision was influenced by the fact he didn't finish at the ironman world championships in Hawaii last October.
"I had a bad Hawaii so I need some qualifying points," he said. "I didn't have the physical strength or probably the mental strength to do a late ironman after the bad Hawaii, so I decided to let it go and try to race as early as possible in the season.
"I was in New Zealand a long, long time ago and I enjoyed it that time. I trained in Christchurch with Dr John Hellemans for several months. So there were a few factors that made me decide to go for Ironman New Zealand."
Vanhoenacker said things hadn't been easy since his world record performance.
"I was very happy to have the record and say, 'okay, you are the fastest guy on the planet'. (But) there was a whole lot more media attention. It kept going the whole summer up to Hawaii and it took a bit of energy out of me, I think."
He has been forced indoors to prepare, although he will base himself in Taupo from next week for the March race.
"Every hard session I do indoors at the moment on the turbo trainer and on the treadmill because it has started to freeze and snow now here in Belgium.
"I spent a month over Christmas at Fuerteventura in the Canary Islands training in the sunshine which gave me a good base, and I recently raced a 70.3 in South Africa."
He plans to also defend his Austrian title in July before preparing for Hawaii in October.
"I think Hawaii for a lot of us guys is the main race. I always said that as long as I feel I can have a shot at a win there I will go back and try again. Every year there are maybe 20 guys who feel they have a real shot."
The full professional field for Ironman New Zealand will be announced next week.