The 58-point thumping in the 75th inter-school between the sides eclipsed Waitaki's 44-5 win in 1998.
Waitaki Boys, which has suffered only one defeat this season, made a great start when winger George Vae'au scored after just six minutes.
But just when it was expected the floodgates would open, St Kevins made progress through the pick and go in slippery conditions and had captain Logan O'Connell across for a try, which halfback Tom Squire converted to level the scores.
Four minutes later, Waitaki right winger Neil Hill went in for the first of his three tries, and two minutes later hooker Michael Familton raced 20m to score beside the posts.
St Kevins lost openside flanker O'Connell and No 8 Sean Conlan in the space of five minutes, and Waitaki promptly ran in tries to midfielder Palavi Tahaafe and first five-eighth Miles Medlicott.
Waitaki shattered St Kevin's hopes from the second half kick-off when the ball was not taken cleanly and Medlicott was in for his second try.
Hill added two more tries, Vae'au got his second and both second five-eighth Goodwin Williamson and No 8 Sam Sturgess got tries to complete the rout.
Waitaki had a superb inside back combination in Medlicott and halfback Tyron Davies.
Davies fired a swift and accurate pass and had variety in his play, while Medlicott produced some hard running, intelligent distribution and a visionary kicking game.
St Kevins fullback Andrew Oughton looked capable but had few chances, while 130kg prop Esafe Havea was the pick of the tight forwards.
A group of former All Blacks who attended either St Kevins or Waitaki Boys formed a guard of honour for the players as they ran on to Centennial Park.
Frank McAtamney (75), who farms at Woodbury, near Geraldine, propped the All Black scrum in the second test against the Springboks in 1956.
The Springboks won 8-3.
McAtamney was a member of the St Kevins College First XV in 1949 and 1950 and recalled beating Waitaki Boys one year and losing the other.
He had returned only twice previously for the annual fixture and said it was a special to return yesterday for the 75th anniversary fixture.
"They've made it an occasion," he said.
Waitaki Boys High School 65 (Neil Hill 3, George Vae'au 2, Miles Medlicott 2, Michael Familton, Palavi Tahaafe, Goodwin Williamson, Sam Sturgess tries; Brad McKenzie 5 conversions), St Kevins College 7 (Logan O'Connell try; Tom Squire con).
Half-time: Waitaki 33-7.
> All Black captain Richie McCaw and former No 8 Buck Shelford will be the special guests at the All Blacks roadshow at the Oval in Dunedin today.
Highlanders captain Jimmy Cowan will also be at the roadshow, sponsored by MasterCard, which runs from 11am to 3pm.
The roadshow allows supporters the opportunity meet the All Blacks and compete against them in a variety of fun rugby challenges.
- Terry O'Neill and Sally Rae
