The 27-year-old Queenslander started the day six shots adrift of Pilkadaris but found three birdies to close the gap on the front nine at the Millbrook Resort before snaking a long putt across the 10th green for an eagle.
Three consecutive birdies from the 14th sent him clear at the top of the leaderboard and, after a duck had been shooed off the green, he nearly landed another long eagle putt at the 17th.
His seventh birdie secured, Nisbet settled for par at the short par-three 18th and watched as Pilkadaris was unable to secure the ace he needed to force a playoff.
It was a third professional title for Nisbet and his tournament total of 27-under 258 was a record, beating the 26-under Australian great Kel Nagle fired to win the title in 1964.
"I'd been aggressive all week, I just wanted to stay being aggressive and just hole a few more putts," Nisbet said.
"Terry inspired me yesterday, he holed a lot yesterday and that was a real inspiration."Pilkadaris, who had been seeking his first title in nearly 13 years, did little wrong in his flawless final round of 70 but simply could not buy a birdie after the 11th hole, despite a string of chances.
Nisbet, who served an 18-month doping ban around the turn of the decade, won his previous titles at the Morobe Open in Papua New Guinea in 2015 and at the Clearwater Bay Open on the PGA China series the following year.
(Reporting by Nick Mulvenney, editing by Sudipto Ganguly)
