When I asked him a few years ago what he thought was his greatest race, he immediately nominated his astonishing performance in the Stadio Olimpico in 1960.
Across his career Snell, who passed away at the age of 80 in Dallas on Thursday lunchtime(US time), broke world records over five distances, including his remarkable 3.54.4 mile at Cooks Gardens in 1962. He also won the 800m/1500m double at the 1964 Olympics in Tokyo, something not achieved before or since.
But his captivating Olympic debut remained his favourite outing.
"It has to be Rome — because of the circumstances," said Snell in a 2014 interview. "I was ranked 25th in the world and some people back home were saying 'Why are you sending him?' There may have been better achievements but they were probably more expected."
At that Olympics there were 51 runners competing for only six spots in the 800m final. It meant four gruelling races in little more than 48 hours, unheard of by today's standards.
The heats were on Wednesday 31 August at 11.00am, followed by quarter-finals commencing at 4:30pm on the same day, when the Italian sun was still burning. At 4.45pm the next day the semifinals were staged, ahead of the final 24 hours later.
"Arthur [Lydiard] kept telling me — you've done more endurance training than anyone else — it's going to pay off," recalled Snell. "Everyone else is going to be tired."
By lunch time on the Wednesday, 24 runners were out. Snell won one of the nine heats and then finished second in his quarter-final, behind pre-competition favourite Roger Moens of Belgium.
Twelve men remained. Snell, who had worn the black singlet for the first time just five months earlier, then won the second semifinal, to reach an Olympic final.
"In my mind I was already a success," said Snell. "There were a lot of thoughts going through my head but I wasn't really that nervous. Even if I ran last I could hold my head high, but I knew I wouldn't run last."
As detailed in the book Peter Snell and the Kiwis Who Flew, four of the six finalists had recorded better 800m times than Snell that year. Apart from Moens, who had held the world record for five years, there was Jamaican George Kerr, German Paul Schmidt (ranked third in the world), highly rated Swiss Christian Wagli and Matu Matuschewski (Germany) Snell had aimed for a fast start, and he got it, but was only fourth heading into the final lap.
"I had my doubts during the race," said Snell. "The fast guys were blasting away and I couldn't get to where I wanted to be."
Around the 600m mark Snell made one of those pivotal decisions in the annals of New Zealand sporting history; like Jimmy Cassidy delaying his charge on Kiwi in 1983, Jeff Wilson's swan dive in 1994 or the Evers-Swindell twins producing that final, desperate stroke in 2008.
He was boxed in on the inside, and could have gone wide for space and a final burst but decided to stay, potentially a dicey decision for his chances of making the podium.
"I had planned to sprint from around 200m but the pace was too fast," said Snell. "Luckily everybody started to die as we went round the corner and I still felt great."
On the world feed, the BBC commentator was warning that "Snell might have difficult getting out...he's trapped on the inside" but space opened up and in a stunning finish, Snell accelerated ahead to take the tape in 1m46.3, a stride ahead of Moens (1m.46.5s) with Kerr was in third (1m47.1s).
Snell had smashed the Olympic record by one and a half seconds, and beaten the world record holder. He had ran three personal best times, in just over two days.
"It's funny how things work out," recalled Snell, who pointed out that as a 17-year-old he wasn't even the fastest among his schoolmates, finishing third in the 880 yard race at the Mount Albert Grammar School.
"I knew I had some potential and ability but it was all the work with Arthur and the boys that set everything up."
"He had an amazing natural talent that was honed by Lydiard's coaching," said Roy Williams, who won decathlon gold at the 1966 Commonwealth Games before a long career as a sports journalist. "However people also overlook his amazing competitive temperament, his ability to find his best performance when it really mattered. He simply loved winning."