Matt Hauser claimed victory at the World Triathlon Championship Finals by just 0.08 seconds from series champion Vasco Vilaça.
Hauser needed to win and for Vilaça to finish sixth or lower to claim a second-consecutive series title.
Lauren Parker became Australia's most successful para triathlete, claiming a sixth world title in the PTWC classification race.
Australian triathlete Matt Hauser showed he was up for the fight at the World Triathlon Championship Finals in Pontevedra, Spain overnight, beating Vasco Vilaça to the line in a thrilling sprint finish.
Defending series champion Hauser came into the series finale knowing he would be up against it to retain his title.
A number of crashes throughout the year meant Hauser needed to win and beat Vilaça by five places.
The Portuguese triathlete was in no mood to let the Australian get any sort of gap though, sticking with him through the swim and shadowing on the bike before the tremendous run stage.
"That's just ridiculous. I was just telling myself I can't lose this one, I can't lose this one," Hauser said.
"I've been so up and down this year and so inconsistent. I just wanted it out there today.
"There is a lot to be thankful for and pleased for. I was happy to get the win out there today and to execute when it mattered.
"I'm not back-to-back world champion, but I can hang my head high. I achieved what I set out to achieve today and now looking onwards and upwards for next year."
Hauser and Vilaça ran away from Olympic champion Alex Yee, whose run leg bought him into contention in the closing stages.
The Briton could not stay with the leading pair though as they engaged in what turned into a battle for the line.
Both men were credited with a time of 1:39:31, but the Australian's dip on the line ensured he would claim victory by 0.08 seconds.
"Credit to Vasco, what a champion," Hauser said.
"I mean we got a bit pushy, shovy in the end. Apologies to him. I gave him a bit of a bump on my way through to get to the line first.
"[But] you have to do these things to get the victory sometimes, to have that dog in you.
"I didn't want to lose the sprint finish to Vacsco. I haven't lost all year to him.
"I have this notch in my belt this year and will take the momentum into next year and to LA2028."
Lauren Parker also claimed victory in the PTWC race in Pontevedra, cementing her status as one of Australia's greatest-ever para triathletes.
PTWC events are for athletes who use a wheelchair in their daily life.
Racers in the PTWC category compete in a standard 750-metre open-water swim, but can use swim-exit handlers to help them out of the water. They then race a recumbent handcycle for the 20km cycling leg, before using a racing wheelchair for the 5km run leg.
The reigning Paralympic champion was never troubled in the race, leading from early on in the swim and thereafter, cruising to victory.
"I felt awesome out there in swim, bike and run," Parker said.
"I got a decent lead in the swim … I got on the bike and I felt so strong out there and I was pulling time into the girls, and extended my lead."
"And in the run, I was just holding them off."
The win secured the 37-year-old multi-sport star a sixth PTWC World Championship title.
It made Parker Australia's most successful ever Para triathlete, beating the Bill Chaffey's previous benchmark of five world championship titles.
"It's just as special as my first title," Parker said.
"My first title was obviously [special because] it was my first. Number six means I've overtaken Bill Chaffey. It's awesome."
Parker won the PTWC class para-triathlon race at the Paris Olympics, having won silver in the same event in Tokyo in 2021.
She then backed up that performance to win para-cycling gold in the H1–4 road race and silver in the H1-3 time trial as well.
Not only that, but Parker can add four rainbow jerseys as a cycling world champion to her triathlon titles.
The Newcastle athlete also took to the snow in the past year, competing in both the biathlon and cross-country skiing at the Milano-Cortina Paralympic Winter Games in 2026.
Elsewhere, Anu Francis secured silver in the Women's PTS2 World Championship race.
The PTS2 classification is for non-wheelchair users for athletes who live with muscle power disorders or limb deficiencies.