Australians have won both the men's and women's contests in the inaugural Auckland Ironman 70.3 race.
Christian Kemp sprinted away from New Zealand's Bevan Docherty five kilometres from the finish to win the men's race, while Annabel Luxford was an easy winner of the women's race.
Kemp and Docherty were together for much of the run before Kemp poured the pace on with 20 minutes to go.
He eventually crossed the line in a time of 3 hours 56 minutes and 3 seconds, 34 seconds in front of Docherty.
Clark Ellice, of New Zealand, finished third.
Kemp, 32, says he surprised himself with the win.
"When I was running with Clark and Bevan, I was just pinching myself. I don't know how I was there and the legs were feeling good," he said.
"I've gone under the radar in most races I go into at the moment, and you have a good day here and there and obviously I had one of them today.
"I'm not sure that I'll be right up with the top guys yet, but I certainly won't be flying under the radar any more."
Brisbane-based Luxford, the former world No.1 Olympic distance athlete, led almost from start to finish to win in a time of 4:19.18, six minutes clear of double world champion Caroline Steffen, of Switzerland, and Meredith Kessler, of the US.