Walsh won in 54.33 seconds at the Fort Lauderdale Open in Florida, where she set her previous world record of 54.60s.

American swimmer Gretchen Walsh has stormed to 54.33 seconds in the women’s 100-metre butterfly to lower her own world record for the fourth time at the Fort Lauderdale Open in Florida, the United States.

Walsh on Saturday sliced 27-hundredths of a second off the previous world record of 54.60 she set in the same pool at a Pro Swim event last May. She broke the record twice in one day at last year’s meeting and has now broken the record four times.

Winner of three world titles in Singapore last year, Walsh is now more than a second faster than the second-fastest woman in the history of the event, with Sweden’s Sarah Sjostrom at her best of 55.48 seconds.

She was more than four seconds faster than world junior record holder Claire Curzan, who clocked 58.44 for silver, and fastest in the world this season by more than two seconds.

Walsh now owns more than a third of the sub-56-second swims in the event’s history.

The 23-year-old joked about making the world record an “annual thing” as she took to social media soon after her feat.

“Could not be more grateful for the WR, the crowd, and the pool,” she said in a post on Instagram.

France’s Olympic hero Leon Marchand captured two titles to take his tally for the week to four.

On Saturday, the four-time Olympic gold medallist won the 200 metres breaststroke in 2 minutes 9.04 seconds, his best time of the season, and followed up with a victory in the 200m individual medley in 1:57.28.

Hungary’s Hubert Kos, who trains with Marchand under former Michael Phelps mentor Bob Bowman in Texas, tied for second in the medley with Carson Foster, both touching in 1:57.95.

Marchand, gearing up for the European Championships starting in Paris on July 31, had used early meets this season to test himself in less familiar events.

But in Fort Lauderdale, the 23-year-old has opted for the same race programme that saw him win four gold medals at the 2024 Paris Games.

Katie Ledecky opened the day with an 8:12.66 in the women’s 800m freestyle to finish more than 30 seconds ahead of 8:40.80 by Katie Grimes.

Ledecky, the most decorated female swimmer in history with 14 Olympic medals, was just off her season’s best of 8:08.57 set in March.