They were at 10-under 134 at the Sunrise Golf and Country Club.
Pettersen, who won in South Korea last weekend beating Matthew in a playoff, recorded seven birdies, four on her last six holes, to catch first-round leader Park.
The Norwegian with eight career victories said a light mood and aggressive game helped her to pull ahead near Taiwan's northwest coast.
''I figured it's time to kind of shift to the fifth gear, and it's nice when the body reacts to your kind of mind game,'' Pettersen said.
Park, who shot a 69, sank four successive birdies to reach 10 under after nine holes, bogeyed the 17th but reclaimed the lead with a birdie on the last.
Matthew started better than she finished, while Tseng struggled to get going after a bogey on the seventh, managing birdies only on Nos. 13 and 18 to stay in contention.
''The crowd goes like crazy,'' Tseng said, describing the reaction at the 18th hole. ''It gave me goose bumps.''