James Magnussen has bounced back from his 100m freestyle frustration to top the 50m heats at the Rio Olympic trials in Adelaide.
He clocked 22.39 seconds to be the fastest ahead of Tuesday night's semi-finals.
The one-lap "splash and dash" is Magnussen's chance to earn an individual Rio berth after being left in Cameron McEvoy's 100m wake.
Dual world champion Magnussen was fourth as McEvoy clocked the third fastest 100m time ever to claim gold on Monday night.
It was just 0.13 of a second outside Brazil's Cesar Cielo's 2009 world record.
McEvoy (22.60) backed up to be third fastest in the 50m heats behind Magnussen and Matt Abood (22.54).
Asked how much focus he had given the 50m, Magnussen said: "Not much up until now.
"This might be the one.
"I don't have to have that endurance in my shoulder - I can just go hell-for-leather."
Magnussen looks set to snare a 4x100m freestyle relay berth when the Rio squad is confirmed on Thursday.
Teenager Kyle Chalmers (13th fastest) qualified for the 50m semi-finals backing up from his 100m silver in 48.03 - a new world junior record that also booked his Rio ticket.
Belinda Hocking and Madison Wilson relegated world champion Emily Seebohm to third fastest qualifier for Tuesday night's 200m backstroke semi-finals.
Olympian Chris Wright is fastest for the 100m butterfly semis.
Jake Packard (50m breaststroke) and Sara Saal (50m butterfly) are fastest qualifiers for their respective finals on Tuesday night.
Also among the six finals on Tuesday night, Bronte Campbell and sister Cate will clash in the 100m freestyle while world champion Mitch Larkin will feature in the 200m backstroke.
Top qualifier Thomas Fraser-Holmes has pulled out of Tuesday night's 200m individual medley final.
He has already qualified for Rio in three events.
National record holder Jess Ashwood (eight minutes, 31.60 seconds) was fastest for Wednesday night's 800m freestyle final.