Australian long-course triathlon stars Max Neumann and Sarah Crowley have had landmark wins at the Ironman WA race.

Neumann, who finished fourth two months ago at the Hawaiian Ironman world championships, went within one second of the course record at Busselton, south of Perth.

He became aware inside the last 10 minutes of his race that the record was within in his grasp, prompting him to launch a powerful sprint down the finish chute.

But after seven hours 45 minutes 21 seconds, he was just shy of the mark set three years ago by British star Alistair Brownlee.

Crowley made history, becoming the first triathlete to win all three Australian Ironman-distance races in the same year.

She won Ironman Australia at Port Macquarie in May and Ironman Cairns a month later before finishing seventh at Hawaii.

The pair dominated their races, with Neumann finishing more than five minutes clear of compatriot Steve McKenna.

"It was about eight minutes left, we had about two kilometres to go, so I did some quick maths and I thought the last thing I want to do is bury myself and end up in the medical tent," Neumann said of the course record.

"I knocked it down in the last K and sprinted up the finish line and missed it by one second. It is what it is."

McKenna took second in 7:50:49, with fellow Australian Matt Burton completing the podium in 7:56:09.

Crowley won the 3.8km swim, 180km cycle and 42.2km marathon run event in 8:46:10, ahead of Dutch pair Els Visser (8:50:49) and Lotte Wilms (8:52:53).

After a couple of tough years personally and professionally, Crowley said she used the Port Macquarie and Cairns races to regain her mojo.

"It's a legacy now, it's something I've done in the sport," Crowley said of the local triple crown.

"I love Australia and it's such a cool way to have a fabulous year after some pretty horrible ones with COVID and everything,.

"I've never been to this race and it's just so good. I'll process it and probably have to think a bit more about my words but I'm very happy with it.

"I had lost my confidence and had to build back in with local racing in Australia and that's why I stuck to it with these races this year and now I feel like I executed what I needed to get done."