CATE Campbell and Cam McEvoy, Australia’s world-leading sprint swimmers heading into the Rio Games, have admitted to choking on the biggest stage after blaming mental frailties for their Olympic disappointments.

On a hugely underwhelming night for Australia - with the exception of Mitch Larkin’s 200m backstroke silver medal - near-unbackable favourite Campbell finished sixth in the 100m freestyle, behind sister Bronte who also missed a medal in fourth.

World champion Emily Seebohm also bombed out in the 200m backstroke semis and the drama came after men’s 100m freestyle gold favourite McEvoy finished seventh behind compatriot Kyle Chalmers a night earlier.

Both McEvoy and Cate Campbell swam times more than one second slower than their PBs in the finals and both admitted to crumbling under a weight of expectation.

‘I GOT AHEAD OF MYSELF’

Campbell clocked 53.24 seconds behind joint winners American Simone Manuel and Penny Oleksiak of Canada (52.70), only a month after sensationally setting a new world record of 52.06.

The 24-year-old is usually one to take the positives from any situation but could only admit she struggled to deal with the expectation and excitement of breaking Olympic records in the heats and semi-finals.

“I think I just went (in with) too much emotional energy in the lead-up and even in that race,” Campbell said.

“I let my head get ahead of me and it’s not something I should do and something that I’ve been working on hard to not to, but maybe I’ve still got another four years left in me.

“It’s always hard, when you’re in form coming into an event, it’s hard not to think about outcomes.

“I think I just let my imagination run away with me a little bit.”

Bronte offered a comforting head on the shoulder as Cate tried to explain the biggest upset of the Rio meet so far.

“This was an Olympic final, I should have stepped up and performed better but that’s the way the chips fell,” she said.

‘IT’S A BLOW TO THE PERSONAL EGO’

Earlier, McEvoy missed a spot in the men’s 50m final then admitted national coach Jacco Verhaeren’s assessment that he suffered stage fright in the 100m final was “probably right”.

McEvoy clocked 48.12 , well off his 47.04 set a selection trials - the fastest time ever in a textile suit.

The 100m performance left McEvoy puzzled but Verhaeren weighed, stopping short of saying the fastest man ever in a textile suit choked but saying it “looked like he was frozen”.

“How do you call it, ‘stage fright’,” Verhaeren said.

“It had nothing to do with any physical, technical, tactical choices whatsoever.

“He just wasn’t there at the right time. And that is mental. And what part of mental we have to find out.”

McEvoy has won plenty of his admirers for how he’s handled his disappointing Rio campaign. He again showed his class again after missing out on the 50m freestyle final, acknowledging Verhaeren may have a point and that “mentally, it felt like a different experience to what I’m used to.”

“If you look at logically, regardless of who says it, it’s probably still true anyway,” McEvoy said after finishing seventh in his 50m semi-final.

“It doesn’t change that fact that that happened and I guess it’s always hard as an athlete to admit when you step up and you don’t quite deliver mentally.

“You always like to think you have some level of mental toughness in a sport. It is a small blow to the personal ego when you accept that.

“I think that’s the first step in realising and improving upon it, accepting it is what it is rather than trying to build a road around it and hoping for the best next time. It’s better to just face it head on and deal with it like that.”

“I’m sure on a stage like this with an outcome like that, there’s no way that it’s not even a little bit mental.”

‘THOSE THINGS CROSS YOUR MIND’

Reigning world champion Larkin came up just short behind American Ryan Murphy in the backstroke final. But his silver was the only bright spot on a night that also featured fastest qualifier Taylor McKeown missing a medal in the 200m breaststroke final.

Larkin seemed reluctant to celebrate his silver too much and was asked to try and explain night’s bizarre events.

“It was a surprise to me as well,” Larkin said of the women’s 100m freestyle.

“I watched the race unfold and in my head I thought ‘OK we’re back in Brisbane racing, you’ve done this 1000 times just go and do it again.

“But then I caught myself thinking you’re not in Brisbane, you’re at the Olympics’ so those thoughts cross your mind.

“I haven’t spoken to them but it’s a massive surprise. I guess it’s about racing and handling that pressure and expectation. Something didn’t’ go to plan tonight and she’ll learn from that and come back swinging. I know she’ll be back.”