Pete Jacobs was well and truly feeling the love after extending Australia's domination of the Hawaiian Ironman triathlon world championships.

The 31-year-old Sydneysider's maiden victory on Saturday (Sunday AEST) continued a sequence in which an Australian has won the men's or women's title every year since 2006.

Former Australian Leanda Cave, who has raced for Great Britain since before the Sydney Olympics, won the women's title, also for the first time.

Cave finished a minute ahead of Swiss Caroline Steffen, while Australia's former winner Mirinda Carfrae collapsed at the finish as she placed third.

Jacobs had a smart race and took the lead midway through the run to win in eight hours 18 minutes 37 seconds.

German Andreas Raelert also collapsed at the finish line as he finished second in 8:23:40, only 29 seconds ahead of Belgian Frederik Van Lierde.

Race conditions were particularly tough, with strong winds on the bike and the usual tropical heat.

But an excited Jacobs was feeling no pain immediately after his win as he celebrated with friends and family.

"I'm in love - I'm in love with the sport, I love my friends, my family, they've done so much for me," Jacobs said.

"Those last two miles, I was running home to Jaimielle, my beautiful wife who I love so much and just saying ... 'love' to myself over and over.

"I am so lucky to have this opportunity to do what I do and have a good day out there with all my friends, family and sponsors here.

"There's so much love."

Asked how he would celebrate the win, Jacobs beamed and said: "We're going to have a party."

Jacobs finished second last year behind three-time winner and countryman Craig Alexander and came into the race determined go one better.

He was within a minute of the lead after the 3.8km ocean swim and trailed Belgian Marino Vanhoenacker by eight minutes 28 seconds at the end of the 180km cycle leg.

Vanhoenacker wilted and Jacobs stormed past him halfway through the 42.2km marathon run.

Alexander was more than 17 minutes down after the bike, but persevered and improved three places to finish 12th in 8:40:49.

Steffen's Australian partner David Dellow made an impressive Hawaii debut, taking ninth in 8:35:02.

Carfrae was well-placed after the bike, eight minutes from the lead, and the women's run course record holder quickly made up ground.

But in the closing stages of the run, she faltered while trying to take second place from Cave.

The British star, who also won the world 70.3 (half-Ironman) title last month, then took the lead from Steffen in the last few kilometres.

Cave won in an official time of 9:15:54, 1:04 up on Steffen, and Carfrae was exhausted as she crossed the line in 9:21:41.

About 2000 triathletes, ranging in age from 19 to 82, contested the epic race and there was a midnight deadline for the last finishers - 17 hours after the start.