Mr Buzzard, a competitive table tennis player, recalls the future prime minister making the wrong call against him when Mr Key was next in line to take the court.
"He definitely called it out when it wasn't. I'll never forgive him for scamming me at padder tennis. I got done over by him."
Mr Key mentioned his run-in with Mr Buzzard when he and Labour leader Phil Goff were being asked a series of questions by the Stuff website to gauge who was the "blokiest".
The questions included whether they had ever thrown a punch or been hit by anyone.
Mr Key named Mr Buzzard, saying: "I don't know if he is still in New Zealand or a voter, but he smacked me when I was at Cobham Intermediate and I still haven't forgiven him."
Mr Buzzard, now a married father of three in Invercargill, told the Weekend Herald the pair were academic and sports rivals, but drifted apart after intermediate school.
"I think it's brilliant what he's done. He's just a general all-round good person. I haven't caught up with him since high school.
"I had an opportunity at a building opening he was doing but he was surrounded by far too many people."
Mr Buzzard, a company chief financial officer, said he was still deciding whether to vote National or Act this year.
In the interview with Stuff, Mr Key also disclosed he had vomited after drinking a yard glass of beer, and would be willing to deliver a big speech without wearing underwear if a hotel lost their laundry.
Mr Goff said he wouldn't touch a yard glass, and would rather go to a shop for help than change a tyre himself.
Both have killed rabbits, but neither would have the nerve to criticise a bad haircut from their wives.
Asked if he had ever thrown a punch or been hit, Mr Goff said: "In my younger days, yeah, I have got to confess that I was a bit more hot-headed and those sort of things happen."
Mr Goff protested strongly against his younger son drinking a yard glass at his 21st birthday party.
"And my wife told me to get real. But I'm not in favour. I drink. I enjoy drinking. But I never drink to get drunk."