"It was a short par four so there was an opportunity to drive the green. It wasn't very long and it was downwind so I was able to drive close to it."
All facets of his long game were pretty solid throughout the tournament.
"I made most of the greens so I didn't really have to chip much."
Duff finished with a three-round, four-under-par 212 (70, 71, 70), leaving him four strokes ahead of fellow New Zealand senior representative Brent Paterson, of Auckland Royal GC.
Paterson carded a sizzling final-round 67, the best score of the championship, but it was too little, too late for the defending champion, who couldn't emulate his heroics of last year at the Ohope Golf Club in reeling in Omanu's Andries Cloetes, who was three strokes in front.
His 77 on Friday had done too much damage as he finished his campaign in outright second place on an even-par 216 (72, 77, 67).
But this year's championship was Duff's domain. His first-round 71 on Thursday included three birdies, an eagle and four bogeys.
The next day he followed it up with five birdies and one bogey and a double bogey before a composed four birdies and three bogeys on Saturday.
However, the 55-year-old found the putting tricky on slick greens. But because he got on the greens in regulation, he eliminated the stress of getting up and down with the putter too often.
The plus two handicapper from Hastings Golf Club also spurned the advances of a few holes that had pot bunkers dotted around them.
"I hit the balls well of the tees so that set me up where I didn't miss too many greens as well."
Even though Paterson was eight strokes behind, Duff said the defending champion adroitly made his charge.
But Duff kept his composure on the platform of building a nice buffer.
"He didn't really come close but he birdied the last to make it a four-shot difference."
The 10-time Hastings club champion will make his debut in the 12-member New Zealand Masters team, with eligibility beginning at 55, to play Australia at the same venue from today.
Duff will make his debut with Bob Shirley, of Kaitaia, after the pair qualified by age for the annual Sanctuary Cove Trophy clash against the holders.
They play foursomes in the morning and four balls in the afternoon, where they each play their own ball but only the best score counts.
Tomorrow morning they will finish with the singles competition. After yesterday's rain, he said the course would be "a lot different". "It'll definitely be much softer so it probably won't run that much and make the course a bit longer but it'll be easier putting because the greens will be softer."
No doubt Duff will take a lot of confidence from three days of sublime golf to take the momentum into the team environment.