Australian Libby Lenton regained the world record in the women's 100 metres freestyle with a time of 53.42 seconds at Australia's Commonwealth Games swimming trials here on Tuesday.
The former world record holder lowered compatriot Jodie Henry's mark by 0.10 of a second.
Lenton, 20, is the world 50m freestyle champion. She also holds the Commonwealth 200m freestyle record, which is 0.42secs outside the world record held by German Franziska van Almsick.
"I'm really excited about the record. I knew the other girls would go fast so I just stuck to my race plan," Lenton said.
"I felt good and I thought I would just go for it. I was planning just to do my personal best time tonight, but I am really excited to get the world record."
She was under the world record set by Olympic and world champion Henry by 0.51secs at the turn before holding on to shatter the mark.
Despite breaking the world record Lenton will still need to finish in the top three in Wednesday's final to guarantee a berth for the Commonwealth Games, getting underway here on March 15.
Lenton first broke the record in the semi-finals at the 2004 Olympic trials clocking 53.66secs before finishing second to Henry in the final. She lost the world record six months later when Henry claimed gold at Athens.
{{/usCountry}}Lenton first broke the record in the semi-finals at the 2004 Olympic trials clocking 53.66secs before finishing second to Henry in the final. She lost the world record six months later when Henry claimed gold at Athens.
{{/usCountry}}At the Athens Games she was part of Australia's world record-breaking 4x100m freestyle relay squad before failing to make the final of the 100m freestyle.
She later recovered from that disappointment to win the bronze in the 50m freestyle.
But Henry promised to meet the challenge laid down by Lenton, heading into the final.
"World records can be broken any day. Who is to say I'm not going to go out and break it again," Henry said.
"Records are there to be broken. I see the ultimate as Olympic gold and I have got that. It is just a big fun game between us. It is nice to have the competitiveness between us otherwise we would not swim nearly as fast as we are."
It was the second world record in two days at the Australian Commonwealth Games trials after Jade Edmistone lowered her 50m breaststroke record with 30.31secs in Monday's heats. She won the final Tuesday in 30.54secs.