Swimming great Kieren Perkins has revealed a panic attack nearly led him to abandon an Olympic gold-medal-winning race that became one of the most enduring moments in Australian sporting history.

On tonight’s Australian Story, Perkins explains that, after a poor showing in the 1,500-metre heats at the 1996 Atlanta games, he considered ditching the final and “disappearing into obscurity”.

His subsequent eleventh-hour comeback to clinch first place earned him his second Olympic gold medal and became a cherished moment in Australian sport.

Eighteen years later, Perkins says it is only now that he can finally understand and articulate what went wrong.

“This whole reality of the pressure of what it was you were going through just collapsed on me,” he said.

“And if I’m honest, I just panicked. The reality was in the middle of the heat, at that heat, I panicked in Atlanta.

“I got to this point where I just realised that the least painful thing to do for me would probably be just to miss the final and disappear into obscurity and tell stories of the good old times about the races I’d won before.

“And it’s not to say that I stopped trying or I gave up, but I certainly stopped pushing and just rolled through the rest of the [heat] at the pace that I was doing, and touched the wall and looked up at the scoreboard and saw the eight beside my name.”

Qualifying by a mere fingernail, the swimming great was largely written off for the final, having been relegated to race in the despised lane eight.

“That was when the real panic set in, because I realised of course I was in the final, I was in lane eight and I was going to have to back up tomorrow and face the world and stand on the blocks and swim, when clearly I wasn’t ready, I wasn’t good enough.”

As the drama reverberated across the athletes’ village in Atlanta – and back home on Australian televisions – it was looking likely Perkins was barrelling towards defeat on the biggest sporting stage the following night.

Self-doubt flooded his mind and it was a feeling he was not used to.

“I started to mentally go off on this ridiculous tangent about how my life was going to forever alter because if I didn’t win this swimming race the sponsors will be gone, the income will be gone,” he said.

“[Swim coach] Mr Carew won’t talk to me because he’ll be so disappointed in what I’ve delivered. My God, if I don’t win this swimming race, my family won’t love me anymore.”

Race anticipation physically and mentally draining: Hackett

Former rival and Olympic gold medallist Grant Hackett says he can empathise with how Perkins felt.

“I’ve had many moments going from that heat swim where it’s felt like a disaster, thinking ‘How am I going to shape up for the final 36 hours later and carry that expectation and actually get up and meet everyone’s expectations of winning?’,” he said.

“And that’s what Kieren had in 1996. Those hours feel like days and you don’t sleep real well, you’re constantly thinking about the race. Physically and mentally and emotionally, it’s just draining.”

“King Kieren” had built a reputation for having honed enormous mental strength. His mind-over-matter approach and his ability to compartmentalise had helped him destroy opponents in the pool.

Yet with just hours to go before the final, Perkins would suffer the ultimate crisis of confidence. “Superfish” had lost his superpower.

“I actually started to get really nervous, like 10-year-old-freaking-out, I’m-going-to-die, my-life’s-over kind of nerves,” he said.

“And as this kind of thing progressed, as I got more and more stressed about what was happening, and I’m sweating and my heart’s exploding in my chest and all of this stuff’s going on, I actually hit this moment where I got angry with myself because of the physical state that I was in, completely ignorant that the emotional triggers were the problem.

“So I kind of gave myself a bit of a mental slap and started to think about what I used to do as an athlete and how I used to cope with these moments as a kid.”

Kowalski terrified of becoming ‘most hated man in the country’

Perkins was not the only one diving into that pool that day who was struggling to contain nerves.

Fellow Australian Daniel Kowalski had qualified the fastest for the final, yet felt enormous pressure around the outcome.

When Kieren wasn’t performing well and things did start to go a little bit pear-shaped I’m sure that his camp would have been very, very concerned.

“I’d been asked a question: what was it like to be the most hated man in the country? Because I had the potential of beating very much the golden boy of the sport,” he said.

“I didn’t know how to deal with this situation, and it really highlighted to me that mentally, I just I didn’t have it.

“I wanted to be that nine-year-old kid in my lounge room again, cheering on the Australian team. I didn’t want to be that guy up in lane four … I was scared to live out a possible dream.”

Tonight, Australian Story will reveal what was happening behind the scenes in the months that led to this dramatic event and how Perkins’s relationship with then-girlfriend Symantha Liu came under scrutiny from his coach and family.

“Obviously things go wrong and people start to panic and when Kieren wasn’t performing well and things did start to go a little bit pear-shaped I’m sure that his camp would have been very, very concerned and wondering, ‘Well what needs to be done?’,” Hackett said.

“We’ve all been through it as athletes, but I think the difference between Kieren and probably a lot of other people in that situation – between really good athletes and really great athletes – is they know how to get themselves back out of it and that’s what Kieren could do really well.”

The program details how Perkins overcame his issues to achieve victory and later make the difficult transition to life after sport.