Libby Lenton's coach Stephan Widmer hopes she gets credit for breaking the 100m freestyle world record, but predicts that regardless of the outcome the star swimmer will set a faster time soon.

Lenton became the first female freestyler to go under 53 seconds in the first leg of the mixed 4x100m freestyle relay on Tuesday night, racing with American superstar Michael Phelps in the next lane.

She hit the wall at 52.99 seconds to crush German Britta Steffen's mark by nearly a third of a second.

While the record breaking swim is yet ratified, Swimming Australia put the wheels in motion for the record to become official by submitting relevant paperwork to the international swimming federation FINA.

Widmer said while he hoped the record would be ratified for Lenton's sake, he wasn't too worried because he knows she can swim even faster.

"This is definitely not the end," Widmer told AAP.

"The most important thing is she keeps on wanting to improve and keeps on pushing through to endure the hard sessions and the pain.

"I hope she gets the credit for it, but for me it is important to know this is what she is capable of and ready for.

"It is more important to me to see how she did it to move forward."

Widmer, who has coached Lenton for four and a half years, said he knew she was ready to break the 53 second mark in the lead up to the world championships.

"I thoroughly thought it was a really great record, but it was at the level she was at," he said.

"A few weeks before the world championships she was ready to take this step.

"Technically, she was ready to do it."

Widmer said Lenton's progress over the past few years, and most recently her stunning effort to claim five gold medals at the Melbourne world titles amid much pressure and expectation, showed a lot about her character.

He added he felt the Duel in the Pool had allowed her to produce her best in a more relaxed environment.

"Probably, throughout the worlds, everything was a bit challenging, everything was a bit different," Widmer said.

Swimming Australia's chief executive Glenn Tasker said Swimming Australia would follow the normal process involved in requesting world record ratification.

"We have already begun the process of submitting the relevant paperwork to FINA," Tasker said.

"FINA will then follow their normal ratification procedures."

Tasker could not confirm when FINA would make a decision on the record but record ratification can take many weeks.

Brought to you by AAP © 2024 AAP