A sizzling Ariarne Titmus clocked the second fastest 200m freestyle in history on Monday, narrowly missing the 12-year-old world record, while Kaylee McKeown swam the year's quickest 200m medley as they ramped up Olympic preparations.
It was an incredible effort by Titmus, who touched in 1min 53.09sec, more than a second better than American superstar Katie Ledecky this season and just outside Federica Pellegrini's world record 1:52.98.
That mark, set by the Italian at the 2009 world championships, came in the era of super-suits, making the Australian's swim on day three of the Olympic trials in Adelaide even more remarkable.
"It's pretty crazy. That record is very old and no one really has been close to breaking it in a long time," said Titmus, who posted the second best time ever over 400m, behind Ledecky, on Sunday.
"I knew that tonight if I swam the way that I wanted to race I had a 1:53 in me. I was pretty nervous, but last night's (400m) swim gave me confidence."
Emma McKeon went out hard and led through 100m before Titmus turned on the afterburners to storm home.
The versatile McKeon, who had already booked her ticket to Tokyo in the 100m butterfly, ended second in 1:54.74 to also qualify.
"I definitely gave it everything I had," said McKeon, whose time was the fourth fastest this year.
A day after smashing the 100m backstroke world record, McKeown backed up by touching in 2mins 08.19secs in the 200m medley, the fastest this year ahead of American rival Madisyn Cox.
"I didn't get much sleep. But you have to come back this morning (for the heats) and tonight, I wouldn't have it any other way, we're racing tough," said McKeown.
"There was some pressure off because we knew I had made the team, but that doesn't mean that we give up on the rest of our races. It's just heads up, bums down and give it our best."
Tessa Wallace finished second but outside the tough qualifying standard set by Swimming Australia.
To make the team for Japan, Australian athletes must match or better the time needed to make the final at the 2019 world championships.
McKeown will also swim the 200m backstroke in Adelaide, with American Regan Smith's world record on the line.
Matthew Temple secured his spot on the plane by winning the 200m butterfly in 1:55.25, as did David Morgan who touched just behind him.
But they have their work cut if they want to challenge in Japan, with Hungary's Kristof Milak swimming four seconds quicker at the European Championships last month.
Jack McLoughlin, who had already qualified for the 400m freestyle alongside Elijah Winnington at the expense of Olympic champion Mack Horton, comfortably won the 800m in 7:42.51, an event added to the Tokyo agenda this year.
Horton finished sixth, culminating a disastrous trials that has seen him fail to qualify in any individual event.
"My goal here was the 400 and 800 individual so those are ticked and I'm really stoked about it," said McLoughlin.
Australia won 10 medals in the pool at the 2016 Games in Rio, matching their feat from London four years earlier, but well down on the 20 they clinched in Beijing in 2008.