Britain's Chrissie Wellington won the women's race in the 140-mile Ironman Triathlon World Championship in Kailua-Kona, Hawaii, on Saturday.
Wellington has been in excellent form in recent months
The Norfolk athlete, who won her ironman debut event last month, took the lead late in the bicycle section and was in front throughout the run.
The field included most of the sport's top professionals, with the men's and women's winner each earning £78,000.
The 30-year-old gave up her job last year and was making her Hawaii debut.
Wellington, 30, beat Canada's Samantha McGlone by five minutes after a gruelling run, in which competitors have to complete a full marathon distance.
Her winning time was nine hours, eight minutes and 45 seconds.
Wellington said: "It's a dream come true. I saw Sam and I knew I needed to just keep pushing hard.
"Some people told me I had a chance, but I didn't really believe I could do it. I was praying I could hold on for the run."
The men's race was won by Australia's Chris McCormack with a fine run.