Olympic 200m backstroke champion Kaylee McKeown clocked a dominant 2:05.66 at the Australian Open on Monday as the world record holder kick-started preparations for the Commonwealth Games and Pan Pacific titles this year.
The 24-year-old hit the wall well ahead of Hannah Fredericks (2:08.80) on Australia's Gold Coast to post the second quickest time of the year behind American arch-rival Regan Smith.
"Honestly, I would have liked to be a little bit faster," said McKeown. "I feel like I've put in good block of training, so I'm a little bit disappointed with the outcome."
The three-day Australian Open is a stepping stone along the path to June's trials where Commonwealth and Pan Pacific Championships rosters will be determined.
McKeown, who has won five Olympic gold medals and six world championship titles, announced last week that the Glasgow Commonwealth Games in July would be her last.
Fellow five-time Olympic gold medallist Mollie O'Callaghan was also in fine form, powering home first in the 100m freestyle.
She touched in 52.66 – the quickest in the world this year – to edge Meg Harris (53.36) and Olivia Wunsch (53.58), while veteran sprint star Kyle Chalmers took out the men's 100m in 48.39.
Former world champion Sam Short proved too hot to handle for Paris Olympic silver medallist Elijah Winnington in the 400m freestyle, surging home in a world-leading 3:42.53 to beat his teammate by almost four seconds.
"I honestly thought with the gap I had I was doing something special, but got to be happy with 3:42," said Short. "I feel so fit at the moment."
Another Paris silver medallist Zac Stubblety-Cook was edged by Bailey Lello (2:09.79) in the men's 200m breaststroke, but favourite Lani Pallister made no mistakes in the women's 800m freestyle, comfortably winning in 8:11.28.
In other races, 17-year-old Sienna Toohey finished strongly to win the women's 100m breaststroke in 1:06.69 and Harrison Turner (1:56.57) came home first in the men's 200m butterfly.