Burton carded a final-round score of 2-under-par 68 to finish on even-par 210, three shots clear of Hugh Harrison (Takapau) and Martin Webber (Royal Wellington).
Heavy rain overnight left the greens flooded and play was delayed while the ground staff fought hard to get the course ready for the final round.
While some of the field might have felt the pressure from the difficult conditions, Burton was applying some pressure of his own on the leading pack, making consecutive birdies on the back nine to jump into the lead.
He made a total of five birdies, coming on the second, ninth, 11th, 15th and 16th holes, which secured his position at the top of the table.
"I finally got it going with a few birdies," Burton said.
"I still had a couple of three-putts, though. I wasn't nervous overall but I was about some of the putts. The greens have plenty of slope on them so you have to be careful.
"I almost chipped in for eagle on 16, but made my birdie and I knew that down 17 and 18 into the wind with my length it would be difficult for the guys behind to catch me."
Burton, who is based in Australia, plans to be back to chase a third senior title.
"It's great to win two in a row. I will definitely be back to aim for three. Hopefully, like a fine wine, I continue to get better with age."
First-round leader Harrison finished the tournament with a three-over par 73, and Webber carded a 72.
Ngaruawahia golfer Philip Hunter, playing in his first senior championship, had taken a one-shot lead going into the final round but slipped back to sixth with a final-round 76.
In Saturday's second round, Cromwell's Kevin Hurley had a hole-in-one using his seven-iron on the sixth hole.
