Australia’s Pete Jacobs cruised to victory in the worlds’ toughest one day endurance races to take his first IRONMAN World Championship in Kailua-Kona, Hawaii on Sunday.

Fellow Australian Mirinda Carfrae grabbed third place behind Leanda Cave and Caroline Steffen.

The 31-year-old Jacobs, second last year to Australian defending champion Craig Alexander a year ago won by five minutes.

"I am so honoured to be the sixth Australian to win this race. So honoured,'' Jacobs said. "I love this sport. I love my wife, I love the world.

"This is a magic moment I will never forget."

Jacobs covered the gruelling course in 8hrs 18min 37sec to finish ahead of German Andreas Raelert and Belgium’s Frederik Van Lierde.

"It was a hard day but a good day and it didn't hurt as much as last year," Jacobs said. "I'm just so happy."

Australia has now won the last six IRONMAN World Championship titles with Jacobs breaking through for his maiden crown.

Jacobs paced himself well throughout the race, finishing the 3.8km swim in the first chase group and less than a minute behind American leader Andy Potts.

Jacobs was second off the bike, more than 8 minutes behind Belgium's Marino Vanhoenacker, and passed him with little more than 10 miles left in the marathon.

Image by Delly Carr/Sportshoot.

Renowned for his running prowess, Jacobs immediately started making up ground on Vanhoenacker. Vanhoenacker faded badly in the run after Jacobs passed him and wasn't a factor at the finish.

He finished well ahead of German Andreas Raelert, who collapsed as he crossed the line, holding off Van Lierde by only a few seconds.

"I'm in love, I'm in love with this sport," said Jacobs, who was able to celebrate with fans in the closing kilometres.

"I'm so lucky to be able to have this opportunity to do what I do."

Jacobs, 31, is the fourth Australian men's winner after Greg Welch (1994), Chris McCormack (2007 and '10) and Craig Alexander ('08, '09 and last year).

Jacobs was in the background pre-race, with all the hype surrounding an anticipated duel between Alexander and McCormack.

But Alexander was 15th off the bike, more than 17 minutes off the pace, and his best hope was a top-10 finish.

Considered a major contender for the win McCormack punctured in the first 40km of the bike and pulled out before Hawi as he steadily lost time to the leaders, trailing by two minutes after the swim.

Carfrae also paced her race well to snare a podium place today having previously one in 2010 and second in 2011.

She was a little slow in the swim, finishing nearly five minutes behind American Amanda Stevens, but unlike last year she did not lose significant ground to the leaders on the bike.

Swiss Caroline Steffen led after the bike, 8:09 ahead and deep into the marathon before Cave moved through to take the lead. Steffen was unable to go with her but gritted it out for second.

Carfrae, who holds the women's run course record, was unable to produce her usual trade mark run, collapsing at the finish.

Men’s Results
1st: Jacobs, Pete AUS  
2nd: Raelert, Andreas GER 
3rd: Van Lierde, Frederik BEL

Women’s Results
1st: Cave, Leanda USA
2nd: Steffen, Caroline SWI
3rd: Carfrae, Mirinda USA