Ashleigh Gentle collapsed to her knees after battling home third in the inaugural T100 triathlon world championships in Dubai, earning the Aussie a massive payday in the innovative new long-course championship series.

Recently crowned Noosa Triathlon champ for a record 10th-straight year, the 2016 Olympian finished second in the season's overall series.

American Taylor Knibb lifted the first-ever global crown with a commanding victory on Saturday, delivering a brilliant performance in the blazing heat as temperatures reached 31 degrees Celsius during a two-kilometre swim, 80km on the bike and a concluding 18km run.

It completed the 26-year-old's perfect streak after wins in San Francisco, Ibiza, Lake Las Vegas, and Dubai, leaving her with a $US310,000 ($480,000) prize in the lucrative new series.

Behind Knibb and Swiss Olympic silver medallist Julie Derron, Queenslander Gentle, who had at one point looked a potential winner during the run, battled on courageously after hitting the wall in the sweltering conditions, and ended up stumbling along on her knees after walking shattered across the line.

The 33-year-old's ample reward for the brutal test, though, was a $US140,000 pay day for her series second-place, following her victories at events in London and Singapore.

"I went for the win and it was so painful," said the former world triathlon mixed relay champion Gentle.

"I gave it everything and got third in the end but I'm proud of my effort. It was pretty brutal. When I wasn't feeling too good and Derron just flew past me on the run, it was super soul-crushing, but I did what I could.

"All the athletes I've been racing this year have been motivating me and inspiring me in training. I feel like I've been applying myself more, better than I ever have, because the level of the women's field is just getting better and better and just trying to keep up is pretty difficult.

"Taylor has just been dominating and when you're racing an athlete like that, it is sometimes really difficult to truly believe that you can beat them.

"But I had this little fire in my belly … I have no reason to believe that I can beat her, but I'm on the start line and that means I have got a chance, so I just had to believe that.

"I didn't beat her but feel like I was a step closer today and did everything I could to try and get there."

Knibb reckoned she was "kind of shocked" by her victory. 

"It only came together in the last 3 kilometres when everyone else fell apart, but it was very step by step."

The T100 series is organised by the nascent Professional Triathletes Association (PTO) as the official tour of long-distance triathlon.

Where Olympic-distance triathlons take place over a 1,500m swim, 40km bike and 10km run, the T100 races take place over a total distance of 100km.

Ironman distance races are more than double that distance, taking place over a 3.9km swim, 180km bike and then a 42km run.

Featuring 20 of the world's leading male and female professional triathletes, the season consists of seven races, culminating in the Dubai series finale.

AAP/ABC