Both swimmers obliterated O’Callaghan’s previous world record of 1:52.85 set at last year’s world titles in Japan where she upset Titmus.

The result means Titmus now holds both the 200m and 400m world records. The top six finishers from the event are all likely to make the Australian squad as the 4x200m freestyle relay team - where the Aussies are favourites for gold.

Coach of both Titmus and O’Callaghan, the legendary Dean Boxall, greeted both women with “Yeah girls, yeah girls, Yes” as they walked into the media area.

Social media went into meltdown after the swim, with people from around the world in awe of Titmus and her epic showdown with O’Callaghan.

“She’s already destroyed most of the world’s best, she keeps doing it on the big stage,” one Facebook commenter wrote.

“And so legends are made, tears in my eyes, thanks girls – women’s sport, wow,” another commenter said.

“It was a phenomenal race. My young swimmer was so excited to watch this unfold. She’s been so inspired by the women this week,” another Facebook commenter posted.

“Dominance,” one simply wrote.

Titmus’s win sets the stage for a titantic clash at the Paris Olympics in just a few months where she and O’Callaghan will come up against Canada’s Summer McIntosh, who has already qualified, and American Kate Ledecky, who is likely to book her place at the USA trials later this month.

Amongst the outpouring of adulation for Titmus, there was also condolences for O’Callaghan who was visibly heartbroken by the result.

“Mollie looked devastated and shocked after that race. Well done Mollie!!! You broke the world record and STILL were beaten!!! Amazing performance use it as motivation to go faster in Paris!!! Be proud!!”

“Gut busting! Imagine beating the world record in the trials and coming second! Thrilled for both girls but a bitter pill for Mollie.

THE TITMUS STORY

Titmus knew instantly she was born to be a swimmer when she plunged into a Launceston pool for the first time while at primary school.

“I remember we did school swimming and I thought, you know, I really like swimming,’’ she recalled to The Courier-Mail’s Andrew Dawson back in 2018 when she was a Year 12 student at Brisbane’s St Peters Lutheran College.

“I was seven so I went and signed up (for club) and started training, racing, and got into it.”

Titmus moved with her family from Tasmania to Queensland in 2015 to chase her swimming dreams, connecting with coach Dean Boxall.

She became a household name at the 2018 Commonwealth Games (alongside her super-enthusiastic dad Steve watching from the grandstands) when she claimed three gold medals in the 400m and 800m individual freestyle events and 4x200m relay.

In 2021 at the Tokyo Olympics, Titmus took gold in the 400m freestyle final, edging out world record holder Katie Ledecky and then went on to set a new Olympic record in the 200m freestyle.