James Magnussen clocked a new personal best time to reclaim his men's 50-metres freestyle national title and the sprint double at the Australia Swimming Championships in Adelaide on Thursday.
The Olympic silver medallist, who successfully defended his national 100m freestyle crown earlier this week, will now have the opportunity to swim in both events at the world championships in Barcelona in July.
Magnussen, 22, was clear of the field at halfway and hit the wall in 21.52sec, a time that would have won him the silver medal in the event at the London Olympics last year.
Matthew Abood, a 2011 world championship relay gold medallist, was second in 21.95sec to touch out Matt Targett by just 0.01 of a second.
"I felt as though I was floating on top of the water tonight," Magnussen said. "I got a good start and felt like I was going from strength to strength during the race.
"To be honest that is just the best 50 I have ever put together tonight. I'm really happy with that."
Belinda Hocking claimed the women's 200m backstroke for her sixth consecutive national title in the world's best time this year.
The 22-year-old dual Olympian turned through 100m in third place, but made her move in the third lap before winning in 2:07.17.
Hocking will be joined in the event by dual Olympic finalist Meagan Nay (2:07.96), while four-time Olympic medallist Emily Seebohm (2:10.26) rounded out the medals.
London Olympian Jessica Ashwood took out the women's 800m freestyle in 8:24.63 to secure a place on her second world championships team.