Kaylee McKeown wins 100m backstroke gold at World Aquatics Championships

Kaylee McKeown has unleashed a sensational swim to come from behind and claim the 100m backstroke gold medal at the World Swimming Championships in Singapore.

The five-time Olympic gold medallist beat her American rival, Regan Smith, in an enthralling final by just under two-tenths of a second.

McKeown turned at the 50 down by 0.22 seconds but powered down the back 50 to overtake Smith and regain her World Championships crown.

Her time of 57.16 seconds was just 0.03 of a second outside Smith's world record and 0.17 seconds below her previous personal best.

"It's a little bit emotional. I've worked so hard just to get myself back into a happy state and, as I've said in my interviews, that's all I'm really focusing on," McKeown said.

On Monday she said she thought her new outlook would allow her to swim faster times in 2026, but the results came far quicker than even she expected.

"I think it just goes to show that a happy swimmer is a fast swimmer," McKeown said.

"I have trained hard, but I wasn't expecting to come out and PB [get a personal best] today," she said.

McKeown has spoken about the pressure she felt at the Paris Olympics and how she had fallen out of love with swimming.

Since then, she has changed coach from Michael Bohl to Michael Sage, moved to the Sunshine Coast and dramatically altered her goals.

She said she did not want to swim the 100m backstroke at the World Championships in Singapore but, once she decided to, she did not care if she came first or last; she just wanted to "have fun".

"I don't think it necessarily means anything to win, and I know that sounds bad," McKeown said.

"I think what means most to me is being true to myself and being strong and coming to these world championships and not fearing.

"There was a lot of comments of me pulling out of the backstroke and saying I was scared to lose — that's not the case at all. If anything, I'm scared to fail myself.

"I've worked really, really hard to get up there and prove to myself that I am a good athlete, I'm a good swimmer, and it doesn't matter if I come first or last.

"I just didn't want to keep steering away from fear because the more that you create fear, it becomes a little bit like a monster.

McKeown also revealed she had been in pain from a recent shoulder dislocation.

"It's been quite irritated, but I've got a good medical team and good physios to help me get through the meet," she said.

As for her rival Smith, when asked if she felt any sympathy for her, McKeown replied: "Not at all."

"I think that's just the nature of it. You've got to be competitive," she said.

Fresh off becoming the second-fastest qualifier for the final of the women's 200m freestyle on Wednesday, Mollie O'Callaghan spoke glowingly of her friend McKeown.

"Can we just say how amazing, Kaylee was," O'Callaghan said.

"I think she's quite inspiring.

"Coming off the Olympics, it's something else, like, you've done everything you want to do. And I know for her there was a big mental block.

She's a tough trainer, like, honestly sometimes she says, 'I'm not doing well,' and then I look at her at training and I'm like, 'What the?… that's bonkers.'"

O'Callaghan said McKeown, like a lot of elite swimmers, tended to be critical of herself.

"That's why we're the best in the world, but to be honest I think she's an absolute beast," she said.

On the pair's friendship, O'Callaghan said they were two "goofy girls".

"We can go away from the pool and have a good laugh about things that aren't swim related," she said 

"We're friends based on just being ourselves," O'Callaghan said.

"So, we get along really well and just talk s*** the whole time."

Lani Pallister was on a hiding to nothing, swimming in the lane next to 1,500m freestyle world record holder Katie Ledecky.

She finished in third behind Ledecky and Simona Quadarella from Italy in second.

Pallister stayed with Ledecky for the first 400 metres, with both swimmers under the world record, but by the 500-metre mark Ledecky had asserted her dominance.

"You can't wipe the smile off my face. I actually had a lot of fun racing that, and any time you're in the pool with Katie and Simona and those girls, it's really special, Pallister said.

She finished in 15:41.18, two seconds outside her personal best, but explained she wanted to push Ledecky as hard as she could before the pain of the fast start became too much.

"I only race Katie three more times in the 1,500 before the LA Olympics," Pallister said.

"So, for me, it was just sticking with her for as long as I can and seeing how long I could hold on for.

"So back to training for that one I guess, working on my back end from now on, but yeah I'm really happy.

Asked what she was thinking as she raced Ledecky in the first 400m as the two swam under the world record line, Pallister responded: "Holly f***, that was kind of it."

The starting pace was just too hot as Pallister turned herself inside out.

"It's kind of funny that I didn't throw up after that one, but I threw up after trials, and as much as I wanted to kick my legs in that last 50, I just couldn't," she said.

"Pallister believes she has the capability to eventually beat Ledecky and is working towards meeting that goal at the Los Angeles Olympic Games.

"Katie's the greatest distance swimmer of all time and arguably the greatest female swimmer of all time," she said.

"I think everyone's goal is to win and I wouldn't be in the sport if I wasn't a competitive person and didn't want to have a gold medal.

"LA is the bigger picture, and I think anyone who's still competing in the sport still wants a goal medal individually," Pallister said.

In other results, Jamie Perkins qualified as the fifth fastest for the final of the women's 200m freestyle alongside O'Callaghan.

Harry Turner qualified for the final of the men's 200m butterfly.