The first-round leader will take a one-stroke advantage and plenty of confidence into Sunday's final 18 holes at Royal Port Moresby Golf Club after tasting success at the Coolangatta Tweed Heads Golf Club Pro-Am last week.
Fellow Australians Josh Armstrong (70), the overnight leader, and Lachlan Aylen, whose 66 was the low round on Saturday, are sitting at 11 under.
"Feeling good, played some solid golf the last few days and it feels good to be in the hunt," said Queenslander Dobbelaar, who turns 25 on Monday.
"I hit the ball quite nice. Quite similar in the last few days. Today I hit a couple more wedge shots close, which was nice to have some tap-ins."
Dobbelaar and Canberran Armstrong, playing together in the final group in the Challenger PGA Tour of Australasia season opener, both birdied the 18th.
The leaders also took a liking to the par-5 ninth, with Dobbelaar and Victorian Aylen both carding eagles.
New South Welshman Jay Mackenzie (68) and Queensland's Brett Rankin (71) are joint fourth at nine under, while defending champion and two-time winner Cory Crawford (2017, 2025) is sixth after a one-under 71.
Locals Cassie Koma (72) and Gideon Tikili (78) are two and seven over respectively.
The PNG Women's Open also got under way on Saturday, with the 15-player field completing the opening round of their 36-hole championship.
Australia's Amelia Mehmet Grohn and Kathryn Norris are joined by Cook Islander Emlay Viking at the top after all three carded six-over 78s.
"I feel good," said New South Welshwoman and defending champion Grohn.
"I hit the driver well today, just didn't really take advantage of it, so if I can do that tomorrow, then I'll be happy."
12°C