Il Nuovo Postiglione - Titmus smashes Ledecky's 400m freestyle world record

The 21-year-old upset Ledecky in the Olympic pool last year to claim gold and has now bettered her arch rival's 3:56.46 world best set at the 2016 Olympics in Rio.

"Oh my God, I've just loved swimming the past six months, just going to training with no pressure and just enjoying the sport," Titmus said poolside in Adelaide.

"Coming here with no pressure, apart from the pressure I put on myself, which is still pretty high, it's just fun.

"I never thought this meet, post-Olympics, I'd be swimming faster than Olympic trials and the Olympic Games. I guess if you keep surprising yourself it keeps the sport interesting," she added.

Titmus was under world record pace for the entire race, turning at the halfway mark in 1:56.99 before bringing it home to huge cheers from the crowd.

Ledecky won the 400 free at the US trials last month in 3:59.52.

But Titmus is not expected to defend her world title against her rival in Budapest in June, opting to skip the event and focus on the Commonwealth Games in Birmingham in July.

It capped an impressive meet for the Australian who won the 200m freestyle in 1:53.31, the third fastest time ever. She beat Ledecky to win Olympic gold in that event too.

Titmus also clocked a personal best in the 100m in Adelaide, but opted out of the 800m.

It was the second world record of the meet after Olympic 200m breaststroke champion Zac Stubblety-Cook smashed that mark on Thursday, hitting the wall in 2:05.95.

- 'Tough' -

Double Olympic backstroke champion Kaylee McKeown swept to victory in the 200m medley in 2:09.15. It was her fourth win of the event after coming home first in the 400m medley and 100m and 200m backstroke.

"It was tough race and tough training and hopefully come back in a few weeks a bit stronger," she said.

Shayna Jack also shone with the world's fastest 50m freestyle time this year, taking the mantle from star veterans Cate Campbell and Emma McKeon who skipped the Australian event and will not be at the world championships.

She touched in 24.14, a personal best, having also swum the year's fastest in the morning heat.

"Amazing feeling. I just wanted to go out there and best my morning swim and I did that so really happy," she said. "It's been a great week. I couldn't have asked for a better week."

Jack, part of Australia's 4x100m freestyle team that set a world record in 2018, is in her first major meet since returning from a doping ban after testing positive for muscle growth agent ligandrol in 2019.

She always claimed innocence and won an appeal to have the ban reduced to two years from four.

She will also swim the 100m freestyle at the worlds after qualifying second in another personal best, behind Mollie O'Callaghan.

Isaac Cooper (54.02) won the men's 100m backstroke to make the Budapest team while teenagers Lizzy Dekkers and Abbey Connor qualified in the women's 200m butterfly.

But Stubblety-Cook missed out in the 50m breaststroke, coming sixth behind winner Samuel Williamson (27.05).

G.Palmiero--INP