Australia’s Ariarne Titmus (right) and compatriot Mollie O’Callaghan react after Titmus won the women’s 200m freestyle final in a new world record time, while O’Callaghan also went under her previous world record to finish second, during the Australian Swimming Trials at the Brisbane Aquatic Centre today. - AFP PIC
Australia’s Ariarne Titmus (right) and compatriot Mollie O’Callaghan react after Titmus won the women’s 200m freestyle final in a new world record time, while O’Callaghan also went under her previous world record to finish second, during the Australian Swimming Trials at the Brisbane Aquatic Centre today. - AFP PIC

BRISBANE: Ariarne Titmus shattered fellow Australian Mollie O'Callaghan's 200m freestyle world record today, touching in 1min 52.23secs just weeks before defending her Olympic title in Paris.

She hit the wall in Brisbane at Australia's Olympic trials ahead of O'Callaghan, who also went under her previous world record of 1:52.85, surging home in 1:52.48.

Titmus went out hard and was 0.81sec under the pace at 100m, holding on as her teammate pushed her to the limit.

"Looking at the results, it's unbelievable. I'm really happy to finally produce a swim in the 200 that I feel like my training reflects," said Titmus, 23.

"I think just the field we have is why we are swimming so fast.

"We push each other every day. To have five girls under (trainer) Dean (Boxall) in that final is unbelievable. It's a credit to him and the programme."

Titmus stunned American great Katie Ledecky to clinch gold in Tokyo three years ago.

She will head to Paris as a red-hot favourite alongside O'Callaghan, who smashed Italian great Federica Pellegrini's 14-year-old world record last year.

"We push each other to the best of our limits," said 20-year-old O'Callaghan of training and racing with Titmus.

"I'm still learning, still getting used to the 200m freestyle. It's a very difficult event to get your head around. The past few days I've just been getting eaten up by nerves."

The pair share eight of the 10 fastest times in history, with Ledecky, Canadian phenomenon Summer McIntosh and Hong Kong's Siobhan Haughey all in the chasing pack.

So far, McIntosh is the only other swimmer to go under 1:54 this year.

Lani Pallister and Brianna Throssell came third and fourth in Brisbane to position themselves to be part of an ominously fast 4x200m relay team.

Titmus has been in top form this week, swimming the second-fastest 400m freestyle of all time on Monday as she also prepares to defend that Olympic title. She is also the world record holder.

Cameron McEvoy, who won gold at the 2023 world championships, will also be on the plane.

He won the men's 50m freestyle in 21.35 ahead of Ben Armbruster to become the first Australian male swimmer to make four Olympics, owning three of the four quickest times this year.

"It's pretty unreal. The job's not done yet, but awesome," said the 30-year-old.

Elijah Winnington qualified for the 800m freestyle, coming home in 7:44.90.

But Sam Short, who boasts the fourth fastest swim in history, set at the 2023 world championship behind Tunisian winner Ahmed Hafnaoui, was second and outside the time needed to make the grade.

"That's probably not as fast as I've been before or wanted to go, but I don't want to peak here, I want to peak in six weeks' time," said Winnington.

Winnington and Short had already qualified in the 400m freestyle, where they are both former world champions and serious Paris medal contenders.

No one hit the Australian qualifying mark – which is more stringent than the official Olympic requirement – in the men's 200m butterfly. - AFP