Swallow, a former World Student Games gold medalist and World Junior Athlete of the Year, smashed the field by finishing more than 11 minutes ahead of Australia's Rebakah Keat, the silver medallist.

The 28-year-old from Loughborough, who represented Britain in the 2004 Olympics in Athens, led from the gun.

She covered the 3 kilometres swim in 41min 47sec, 49 seconds ahead of Australia's Pip Taylor.

It was a lead she never relinquished.

Swallow then completed the 80km cycle ride in 2 hours 04min 54sec and the 20km run in 78:18 to cross the line in 4:07:38, 11:11 ahead of Keat.

France's Delphine Pelletier of France won the bronze medal.

Swallow, who had been successful in Olympic-distance races in 2008 with third places at Chicago and London and New York, has made a superb distance step-up to the longer event.

She follows a list of British winners that includes Bella Bayliss in 2006, Leanda Cave in 2007 and Chrissie Wellington in 2008.

Swallow said:  "Everything came together really well for me out there so I couldn’t be happier.

"I went to the Olympics [in Athens] and that was a tough experience but you learn and you move on, so to come back and win a World Championship is very pleasing.”

Keat said: "I tried to mount a challenge but Jodie was on another planet, so full credit to her, she was outstanding.

"Look, I’ve just won a silver medal in a World Championship, so I shouldn’t get too down on myself, but it was a bit ugly out there towards the end.”

American Tim O'Donnell won the men's title in 3:48:15, holding off the challenge of French silver medallist Sylvain Sudrie while Denmark's Martin Jensen took bronze.

Britain's Paul Ambrose finished fifth.

O'Donnell said: "Man, that swim was rough; I was happy to get out of the water.

"The wind just threw up so much chop you could hardly see where you were going.

"But I just built into it on the ride and put myself in a good position behind a couple of guys I was confident I could pick up on the run.

"Sylvain [Sudrie] is a great runner so he was tough to drop out there but I think I put together a very sound race today."