A second bogey on the fourth was merely a blip as he regained his momentum with three more birdies helping him to a strong score.
"I'm very happy and very excited," said Jones. "Last year was a little tough. I took the year off and did the right thing and looked after my wife, so I'm happy I'm able to play again.
"When I started, it was gusting pretty high and raining, and I thought, 'it's going to be a tough day'.
"I got off to a pretty shaky start but managed to chip one in on my third hole. That got me going and I just took it from there."
Palmerston North product Munn enjoyed a "crazy day" and was pleased with a top-three finish after making his pro debut at the New Zealand PGA event at Remuera last week.
The 25-year-old began with an eagle and claimed four birdies to enjoy a share of the lead early on but slipped with bogeys on the third and 18th.
"It was a good day and I'm really pleased with that score," he said. "That wind and rain came in and you didn't know which way the wind was coming from and it was a bit of a guessing game really."
Tournament favourite Ryan Fox fought his way back to tie for 10th with fellow Kiwis Peter Smith and Craig Palmer at two under.
The 29-year-old began his round on Millbrook's back nine, with bogeys on the 15th and fourth holes the only blemishes, while back-to-back birdies on the 16th and 17th and another pair on the second and fifth holes assisted his cause.
"I was very happy," said Fox. "It was one of those days where you could play your way out of the tournament really easily.
"There were a few things I don't think I've ever seen happen on a golf course with a bit of wind blowing in different directions on the same hole.
"Hopefully tomorrow it's not too windy and we can make a few birdies out there and put some good scores up."