The world number two and overnight leader overcame a frustrating day with the putter by picking up three birdies over the final five holes to card a three-under 69 and join big-hitting Spaniard Carlota Ciganda at the top of the leaderboard.
Ciganda made the most of her prodigious length off the tee to offset two bogeys with eight birdies for a best-of-the-day six-under 66, two strokes clear of fellow Spaniard Azahara Munoz, who is alone in third place on seven-under.
World number one Lydia Ko remains on course for a hat-trick of wins following recent triumphs in Australia and her native New Zealand, the 17-year-old carding a two-under 70 to join Stacy Lewis, Karrie Webb and Jenny Shin on six-under overall.
For Park it was another case of staying patient to gain rewards after she waited nine holes for a birdie on Thursday and followed that up with 13 straight pars on Friday before finally moving under par for the day with an impressive downhill putt.
The breakthrough ended a frustrating run of near misses and shaved cups and once she found her range on the greens, she drained another lengthy birdie putt on the 15th and completed her round in style with the big-breaking putt on the last.
“None of my putts wanted to drop today,” Park told reporters. “It could have been a better day but I’m really satisfied the way I finished, especially bogey-free through two days is a great result.”
Park has five major victories among her 19 professional triumphs but the $1.4 million restricted-field event in Singapore is one of the few big tournaments she has yet to win and the 26-year-old will be desperate to change that this weekend.
Ciganda enjoyed a stellar career on the Ladies European Tour before shifting her focus to the LPGA and while she has yet to score success on the American-based circuit, her play on Friday suggested that elusive victory is not far away.
“I’m feeling confident, hitting the ball well and am happy with my caddie,” she said.
“My dad is here, my uncle and other friends. We are having a great time outside the golf course and I think that’s also very important to enjoy yourself when you’re not playing.”
Munoz suffered a heart-breaking loss to Paula Creamer a year ago when the American drained a 75-foot eagle putt for victory in a playoff and while the Spaniard admitted it was a better way to lose than to a scrappy bogey, she felt the tight Serapong Course was good for her concentration.
“Sometimes when courses are wide open and stuff, I have a hard time focusing. That is definitely not the case here,” she said.
(Editing by Patrick Johnston)