Lisbeth Trickett on her way to a new world record [GALLO/GETTY]

Sophie Edington lowered a day-old world record in the women's 50-metre backstroke at the Australian swimming championships and Olympic trials.

Edington finished in 27.67 seconds to break the mark of 27.95 set by her Australian teammate Emily Seebohn in the semifinals on Saturday.

Seebohn did not race in the 50-metre final because it is a non-Olympic event.

Edington and Seebohn will race Monday night in the women's 100 backstroke, an Olympic event on the program for Beijing in August.

Trickett breaks butterfly record

Earlier, Libby Trickett was on track to break an eight-year-old world record in the 100-metre butterfly, but Inga de Bruijn's Sydney Olympic mark was ultimately safe.

Trickett, formerly Libby Lenton and swimming under her married name for the first time, finished Sunday's race in 56.81 seconds after being .22 seconds under Dutch swimmer de Bruijn's mark at the halfway mark.

Trickett won five gold medals at last year's world championships in Melbourne.

Edington's world record was the third in two nights at the trials, which end next Saturday.

Stephanie Rice broke the world mark in the 400-meter individual medley, finishing in 4 minutes, 31.46 seconds.

That took 1.43 seconds off American Katie Hoff's mark of 4:32.89 set on April 1 at last year's world championships.

Seebohn on Saturday took 0.05 seconds off American Hayley McGregory's record set two weeks ago.

Source: Agencies