The pair often engaged in conversation between exchanging clubs and pencils and the veteran even offered him some advice.
"He said it'll help me if I swing slower because there's less danger [of straying shots]," said the youngster who received the annual national Attitude Award last December in the People's Choice category.
Charles, who gave the teenager $50 after the round, used his hybrids liberally, Harrison disclosed.
The jovial left hander, who played alongside three Bay businessman, told fans the course was more difficult than Hastings Golf Club in Bridge Pa where he had a penchant for carding 63 during the former Wattie's Open tournaments.
"I had a seven on a par 3 today, which wasn't very pretty, so with others watching it was somewhat embarrassing for me," he said with a laugh after carding 81.
He had found the bunker and took three shots to get out and as many to putt.
Having set foot at Napier 30 years ago, he said it was imperative to position one's tee shots to steer clear of trouble in what was unfamiliar territory for him.
"I went out of bounds twice and there are a lot of holes where you can't go out of bounds but it was enjoyable and the club does a terrific job of maintaining the course here."
He enjoyed the turnout with the junior golfers in the morning "but I'm not sure if anything sunk in for some of them who are beginners".
"The future of the game is young people who come along," he said, highlighting dwindling membership as a global phenomenon.
Charles said he was a "ball freak" and felt nowadays not enough children get off the couch .
"It's really sad. All I was interested in high school was getting out on the cricket pitch or the golf course."
While education is important he feels sport is an integral part of it, too.
He reiterated the significance of Kiwi professional Lydia Ko as a godsend beacon to keep young girls away from sedentary lifestyle choices and entice them to pick up golf club.
The cost and time it takes to play makes nine-hole courses and shorter tees vital.
"That's [cost/time] a big turn off for people."
Charles was pleased to see Napier club resident professional Andrew Henare organise the pro-am with the help of Bay sponsors.
"I think it's a great exposure of the game and great publicity.
"With every bit of publicity that the game of golf gets is good in promoting and encouraging people from the age of 5 into the game," he said, taking his cap off to the protagonists for reviving a tradition (pro-am) that he suspected hadn't been staged at the club for three decades.
He was booked to play in a pro-am at Russley Golf Club, Christchurch, for seniors (over-50s) in a fortnight.
"We used to play in a regular pro-am called the Garden City in the 60s and 70s in Christchurch and they're trying to resurrect a one-day one at Russley."
Charles said he would love to return to tame the Napier club course after yesterday's "embarrassment".
"I'll be 81 next year so maybe if I shoot 81 next year I'll equal my age or, hopefully, better it."