Kaylee McKeown has nudged her world record when swimming the second-fastest women's 100m backstroke ever - and is disappointed.
McKeown came within eight-hundredths of a second of her global benchmark on Tuesday night at Australia's Olympic selection trials in Brisbane.
As Mitch Larkin missed his initial opportunity to become the first Australian man picked to swim at four Olympics, McKeown fell just short of her lofty standards.
She won in 57.41 seconds, nearing her record of 57.33 set in Budapest last October.
"I'm a little bit disappointed," McKeown said.
"But I have booked myself another ticket to Paris so that's just another chance to go faster."
The 22-year-old now holds the six fastest times in the event's history.
The reigning Olympic 100m and 200m backstroke champion is adding the 200m individual medley to her program at next month's Paris Games.
McKeown on Monday night set a Commonwealth record in the medley, a feat that may have denied her a fresh backstroke benchmark.
"If you're going to get up and do a 200 (medley) at max effort, you're not going to come in the next day being refreshed - no matter what you do," she said.
"The Olympics is just like that. If all goes to plan I will have nine individual events plus relays, so I have got to put myself in harm's way here."
Freestyle ace Mollie O'Callaghan finished second in 57.88 to secure a spot in what she described as her "fun event".
But given her packed freestyle schedule, O'Callaghan may opt out of the backstroke in Paris.
"I don't know yet. It really depends on if I qualify for the next few (freestyle) events, that's the main thing," the 200m freestyle world record holder said.
"The 100 backstroke for me is a fun event, I don't really train for it, so to go out there and do a 57 is just amazing."
Triple Olympian Larkin finished fourth in the men's 100m backstroke final, missing his first chance at creating history by becoming the first Australian man selected for four Games.
Isaac Cooper won in 53.46 ahead of Bradley Woodward (53.53), Enoch Robb (54.14) and Larkin (54.22), who has a 200m backstroke to come on Friday.
All four were outside of the automatic Olympic qualifying time set by Swimming Australia, with selection now at the discretion of hierarchy.
"We just have to see what Swimming Australia will decide," Cooper said.
In the women's 100m breaststroke final, Jenna Strauch (one minute 06.90 seconds) pipped Ella Ramsay (1:06.94).
Max Giuliani won the men's 200m freestyle in 1:45.83 from Thomas Neill (1:46.02).
