World No.1 golfer Lydia Ko has been pushed back into a tie for 27th after the second round of the latest LPGA tournament in Michigan.
Despite shooting successive rounds of one-under 71, the New Zealander is nine strokes behind the leader from Thailand.
Ariya Jutanugarn, targeting a third straight LPGA Tour victory, splashed a long bunker shot for a tap-in birdie at the final hole to earn a two-shot lead after two rounds of the inaugural event in Ann Arbor.
Ariya, who began one shot behind overnight leader Christina Kim, made nine pars on the front side, before clicking into gear after the turn to shoot 68 for an 11-under-par 133 halfway total at Travis Pointe Country Club in Ann Arbor.
The 20-year-old Thai finished with a flourish at the par-five 18th, where her second shot clattered into a grandstand but ricocheted into a greenside sand trap, from where she demonstrated her deft touch.
The closing birdie gave her some breathing room ahead of a trio equal second on nine-under 135 -- Americans Kim (71) and Marina Alex (67) and Ryu So-yeon of South Korea (67).
Coming off back-to-back wins at the Yokohama Tire Classic and Kingsmill Championship, Ariya played with world number one Lydia Ko of New Zealand, who posted her second successive 71 for 142.
The Thai said the course had firmed up since her morning round on Thursday. The course condition, allied to her length off the tee, has prompted her not to carry a driver in her bag this week.
"I didn't hit my iron that good but still OK and I start to make some putt on the back nine," she told reporters.
"Today is a lot more firm than yesterday, so it's really hard to approach on the second shot."
Ariya is trying to become the first player to win three in a row since South Korea's Park In-bee three years ago.
She said she was not thinking about the possibility of winning three straight, at least not yet.
"I'm really happy with it and I really enjoy golf right now."