Americans Alison Walshe and Irene Cho were tied for second with Karine Icher of France and Caroline Hedwall of Sweden.
After an early bogey on the par-3 second hole, Pettersen ran off six birdies before bogeying the 16th, also a par-3.
"I feel pretty good with my game," Pettersen said. "I feel my ball striking is pretty much where I want it to be."
Local favourite Yani Tseng, the 2011 Sunrise champion, only managed a disappointing 76, while Lexi Thompson of the U.S. shot 74.
Tseng said she was thankful to the Taiwanese fans for sticking with her as she struggled through her round.
"I need to be more confident," she said. "I need to believe in myself a little more."
Even with a victory in Taiwan, Pettersen cannot overhaul Park atop the rankings this week. But a good result by her would set up a tight finish to the LPGA season, with two tournaments still to come.
Park is not playing in the Taiwan event.