Gretchen Walsh washed another layer of speed over the shore of 100 'fly here in Singapore today, her latest wave of dolphin brilliance introducing the era of 54-point racing to World-Championship waters.

The top pace there'd ever been since the showcase got underway in 1973 was the 55.53 in which Sarah Sjöström, of Sweden, set the World record championship back in 2017 a year after she'd become Sweden's first female Olympic champion in the pool in a global standard of 55.48.

And that's where the marks stood until Walsh, coached by Todd de Sorbo at the University of Virginia, arrived on the scene with a unique style and way of riding the wave to a pioneering pace on sprint butterfly.

At a glance - The Walsh World-Records Era:

Out in 25.16, Walsh was 0.16sec inside her own world-record pace at the turn. Her return was also the fastest of all homeward lengths, at 29.57, leaving her a touch shy of the 54.60 global standard she set in Fort Lauderdale in May.

An astonishing effort, especially in light of the illness she's recovered from. On how she overcame the gastroenteritis that has rocked the USA team since infection on a pre-event camp in Thailand, she said:

“It took a lot of guts. I think I just wanted to go out here and do it for my team. Represent the flag well and I think that race just… It came out of somewhere. But I’m really, really happy.”

On her winning pace, Walsh said:

“I feel great about it. I was not expecting that time for myself. I think I've had to reevaluate my expectations for myself over the course of this meet. I know it's only been two days, but I wanted to go in just executing the race like I knew how. If that was gonna be a 55, that was gonna be 55, and I was gonna be happy with that, but the fact that it was a 54.7, second fastest time ever, very close to my personal best and the world record.

I'm over the moon. I'm really happy that when it mattered, I was able to do that and just get my hands on the wall. I’m so happy to be under 55 again; it means everything. It was not easy. And I’m just really proud of myself for that time. And giving myself grace throughout this whole process.”

Given that no others in the hunt and headed to the podium had ever swum inside 56sec before the final, Walsh had some wriggle room as far as making sure the colour was gold. As Roos Vanotterdijk stopped the clock in a national record of 55.84 to take an historic silver for Belgium, the gap between the top 2 was confirmed: 1.11sec. That's the second biggest margin of victory since 1973, the record established at 1.41sec by Sjöström ahead of Denmark's Jeannette Ottesen in 2015 not quite the biggest margin.

The Walsh household and Team USA did not only celebrate one Walsh this day: Gretchen had swum down, had the medal hung around her neck and stood for the Star Spangled Banner before watching elder sister Alex race to silver behind Canadian superstar Summer McIntosh in the last final of day 2, the 200m medley.

The 100 'fly bronze went to another star rising at these championships at the start of a new Olympic cycle: Australian Alexandria Perkins surged to the bronze in 56.33, out-touching the four women within half a second of her on 56s, including Olympic medallist at the past two Games, Zhang Yufei, of China.

The History File and What They Said follows ...