They wouldn't know it, but as the two top female athletes faced the final battle of a brutal race, this thought would keep them placing one foot in front of the other.

From the outset, last year's Port Macquarie 70.3 Ironman champion Lisa Maragnon took the fight to the field of women's professionals.

But first-time full distance Ironman Australia competitor Mel Hauschildt was hungry for the win, and a chance to test her ability in the long-haul race.

In the end, she'd claim her victory.

She closed in on Maragnon's well-maintained lead with 25 kilometres of the run to go.

"I've been told anything can happen in an Ironman," Hauschildt told the Port News. "They say a race doesn't start till 30km into the run." And that was her fuel, she said, for trying to close in on what started as a seven minute gap on the run.

By the time the race "really started", the former steeplechaser had taken a two minute, 10 second lead on Maragnon with her trademark run.

And, would finish her first full Ironman at an impressive 9 hours, 28 minutes and 42 seconds.

But the Maroubra mother didn't give up the fight.

"That's when all your training comes into it," Maragnon said of the moment Hauschildt flew past. That's when you trust your training is going to pay off.

"You never know what can happen in an Ironman."

Maragnon finished at 09:30.49, followed by New Zealand's Melanie Burke at 9:32.52.

Both women praised the efforts of the champion.

Hauschildt's feat is all the more impressive considering her last minute decision to compete.

"I decided to do this only three weeks ago and had two weeks off before that," she said. It felt amazing crossing that line that was the toughest thing I've ever done it just goes on and on, it was not fun at all."

The title of Ironman Australia women's champion adds to the Sunshine Coasters impressive track record.

She's won back-to-back in Abu Dhabi, has two Ironman 70.3 World titles in three years and is an ITU Long Distance World Champion.

But Sunday's race, she admitted, was an entirely new beast to battle.

"It was so tough," she said. "I'd never run that far before, I was just thinking never again, never again."

Hauschildt's win marks the first step towards tackling Kona and the greater goal of becoming an Ironman World Champion.