Lydia Ko is in a strong position for another top finish on the LPGA Tour.
Ko is at eight under par through two rounds at the Kingsmill Championship in Virginia, after a second consecutive round of 67.
The 20 year old carded a bogey-free round, putting together an excellent back nine to remain in a share of third, four shots back of leader Lexi Thompson.
Ko birdied her first hole of the day, before reeling off nine consecutive pars to stay steady through the middle of her round. She hit 17 of 18 greens in regulation, but didn't find the same success with her putter, requiring 31 putts for her round.
However, she cashed in on her back nine, with three late birdies putting Ko in position for her sixth top ten finish in 10 LPGA Tour events this year.
"It was a pretty steady round," said Ko, who said the slope and speed of the greens made putting difficult.
"The front nine I gave myself a lot of chances for birdies and a lot of them slipped by. Because the greens are faster, even though you're on the green it's not an automatic two putt either."
Ko's position as world number one has been under pressure recently from two challengers, Korean So Yeon Ryu and Thailand's Ariya Jutanugarn.
With Ko not having won for 10 months, it has given Ryu and Jutanugarn both a chance to snap Ko's 82 consecutive weeks at the top.
They would need to finish ahead of Ko this weekend, and that will require a strong final two rounds, with Ryu in a share of tenth at five under, and Jutanugarn tied for 25th at three under.
With her rivals closing in, Ko believes she has turned a corner and is slowly finding her best form after a comparatively poor stretch to start the year.
"I didn't feel like everything was on - I was really struggling with my short game. Even if I putt good, if the long game isn't there, there's a limit on how low you can go.
"Hopefully that's gone away, and having my good finish in Hawaii I think builds confidence, especially with all the changes it takes time to get used to, but I think everything is going in the right direction."
Elsewhere, Danny Lee is the only New Zealander to have made the cut at the AT&T Byron Nelson event on the PGA Tour. Lee shot a second straight even-par 70 to sit in a share of 51st, 12 shots off leader Jason Kokrak. Fellow Kiwis Steven Alker and Tim Wilkinson missed the cut by two and three shots respectively.