Lydia Ko has shot into contention at the Women's PGA Championship following a six under 66 in her second round at the Kemper Lakes course in Chicago.
The New Zealander shot the round of the day in favorable morning conditions to sit just two shots off the leaders.
Another former world number one, South Korean Ryu So-Yeun, compatriot Park Sung-hyun and Canadian Brooke Henderson are in front at six under for the tournament.
Thailand's Moriya Jutanugarn is tied with Ko in fourth at four under.
Ko's second round was a stark contrast to her first, before she started the day she was in danger of missing the cut.
"I said first of all my goal is to make the cut," Ko joked.
Ko said she hit the ball better on Thursday, but the putts were dropping on Friday.
"It shows how important putting is.
"I just couldn't get anything rolling (on Thursday) so just to be able to make a birdie on the first hole was a huge momentum changer".
Henderson, in the hunt for her second victory in the event after beating Ko in a playoff in 2016, banged in a 15-foot birdie at the last to earn a share of the lead.
"Up and down all day," she said of a round that included five birdies and four bogeys.
"I would like to shoot a little better but one-under when it was so hot and so windy, I'll take it."