Summer McIntosh bagged her third world record in days on Wednesday, clocking 4min 23.65sec to better her own 400 medley record at the Canadian Swimming Trials in Victoria.
The 18-year-old Canadian prodigy, a three-time Olympic gold medallist, laid down another impressive marker ahead of next month's World Championships in Singapore with a dominant performance.
McIntosh's blistering time beat her old mark of 4:24.38 set in Toronto in May last year at the Canadian Olympic trials.
McIntosh's assault on her own world record got off to a smooth start, with the teenager completing the opening butterfly leg in world record pace.
She was more than a second ahead of the world record at the halfway stage, and although that margin dropped to one-tenth of a second after the breaststroke, she produced an electrifying freestyle down the stretch to complete a scintillating performance.
"Going into tonight, I knew I could do something really special because this has probably been the best meet of my career," McIntosh said afterwards in a pool deck interview.
"World records are made to be broken. So by the time I leave this sport, I want to make sure that that record is as fast as possible.
"That really keeps me going, because I know there's always going to be the next generation of kids growing up, and they're going to be chasing the record. So I've gotta give them my best effort to see how long it can stand."
Wednesday's record-breaking display was the latest entry to an impressive catalogue of performances she has produced this week in British Columbia.
On Saturday, she smashed the women's 400m freestyle record, slicing more than a second off Australian star Ariarne Titmus's world best from 2023.
She then clocked the third fastest 800m freestyle in history on Sunday, before diving back into the pool on Monday to obliterate Hungarian great Katinka Hosszu's decade-old 200m medley world record.
McIntosh, who gold medals in the 200m butterfly, 200m medley and 400m medley at last year's Paris Olympics, will now head to next month's worlds aiming to add to her collection of four world championship gold medals.