Wurf, who is also a professional cyclist with the Ineos-Grenadiers team, has twice held the bike course record at Hawaii.

But the Tasmanian flipped his usual script. Instead of being at the pointy end of the race after the bike leg then fading, he started the run well off the lead in 18th place.

The 41-year-old then ran his way into seventh place, clocking 7:51:26 for the 3.8km swim, 180km cycle and 42.2km run event.

Wurf's best finish at Kona was fifth in 2019.

Lange, 39, previously won Hawaii in 2017 and 2018 and on Sunday (AEDT) he beat Dane Magnus Ditlev by nearly eight minutes, with American Rudy Von Berg third.

"I always said my best year was yet to come and no-one believed me," a fired-up Lange said.

"It's amazing, I can't believe it … I just feel grateful."

Sam Laidlow of France, who won the men's Ironman world title in Nice last year, led at the start of the run after smashing his own bike course record with 3:57 — the first man to go under four hours at Hawaii.

But Laidlow detonated on the run and did well to finish in 18th, while Australian Nick Thompson was 21st and compatriot Sam Appleton crossed the line in 24th.

Breaking eight hours at Hawaii was long considered triathlon's holy grail. Lange first achieved the feat in 2018 and this year, the top 16 finishers finished under that mark.

This is the second year that the men's and women's Ironman world championships have split, alternating between Hawaii and Nice.

AAP