Sophie Edington snatched the world record for 50 metres backstroke at the Australian Olympic trials on Sunday while the previous holder watched from the stands after electing to skip the race.
Edington stopped the clock at 27.67 seconds to win the final and slice 0.28 off the record set by Emily Seebohm in the semi-finals just 24 hours earlier.
Seebohm, a 15-year-old schoolgirl, pulled out of the final to concentrate on the 100 backstroke because the 50 is not an Olympic event and would not help her make the team for Beijing.
Seebohm set the fastest qualifying time for the 100 when she won her semi-final in 59.78, joining American Natalie Coughlin as the only women to break the one minute barrier, which she said was her focus.
"The job is not over yet, I still have to make the team tomorrow night," Seebohm told reporters. "It is the first time that an Australian girl has gone under one minute and I am absolutely ecstatic about it."
Libby Trickett (nee Lenton) joined Inge de Bruijn as the only women to break 57 seconds for 100 butterfly when she won the final in 56.81, just ahead of Jessicah Schipper, the 200 world record holder.
Trickett is hoping to qualify for six events in Beijing after winning five gold medals at last year's world championships in Melbourne. She said winning her first final had boosted her confidence.