Olympic champion Kyle Chalmers won the 100 metres freestyle title at Australia's national championships on Friday.
On the comeback trail from injury, Chalmers posted a time of 48.04 seconds on the Gold Coast, the year's second-fastest time behind Hungarian Kristof Milak's 48.00 in March.
Chalmers said he had hoped to break the 48-seconds mark but was satisfied with the swim in just his second meet back since shoulder surgery.
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"I know it’s just going to get faster. I love racing fast and I don’t like giving myself excuses for being in hard work," Chalmers, who won the 200m freestyle title on Thursday, told Australian media.
"It would have been really nice to crack that 47 but it’s only my second competition back."
Emma McKeon announced herself as a contender for the women's 100m freestyle gold by claiming the national title in a time of 52.49 ahead of former world champion Cate Campbell.
"I always mainly trained for the 200, and come down to 100," said McKeon, who won 4x100m relay gold with Campbell at Rio.
"So to be getting those times, that gives me a lot of confidence."
Australia's Olympic swim trials are in June.
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After winning the women's 50m backstroke on Thursday, 19-year-old Kaylee McKeown claimed the 100m title in 58.60, edging 11-time winner Emily Seebohm.
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