Lydia Ko produced a spectacular second-round finish to jump to second in the JTBC Founders Cup in Arizona.
The 16-year-old New Zealander picked up six shots over a six-hole stretch to card a six-under-par 66 in the LPGA event at the Wildfire Golf Club in Phoenix.
That put her 11-under after 36 holes, two shots behind fellow LPGA tour rookie Mirim Lee.
South Korean Lee had a 67 to retain the lead she held overnight while Karrie Webb was the best-placed Australian in a tie for 13th at seven-under.
Ko began the day tied for 11th and was at even-par through the front nine after an early bogey was cancelled out by a birdie at the ninth.
Her big run home began with birdies on the par-four 12th and 13th holes.
The world No.4 followed with eagle-birdie-birdie on holes 15 to 17.
Ko said it was case of getting her approaches closer to the pin on the back nine, citing her 3.5-metre birdie putt on the 12th green.
“It was all that range,” she said.
“I didn’t really hole a long one. Those kind of putts, if some of them drop, they’re birdies. You don’t expect to hole everything, but a couple at a time is good.”
Having moved down the leaderboard during the first half of her round, Ko admitted she was surprised to see herself now sitting so high, but she was pleased with her performance.
“I just gave myself more opportunities on the back nine,” she said.
A two-time winner on the LPGA tour as an amateur, Ko turned professional late last year.
In her four tournaments on the circuit in 2014, she has finished in the top 20 each time, and twice in the top 10.