Ryu opened the year with eight straight top-10 finishes, including the major victory. She struggled in her two events after that run, finishing 56th and then missing the cut at the ShopRite LPGA Classic this month in New Jersey. Coming off a two-week break, she has returned to her early season form -- and then some.

“I played really well the beginning of this year, then I didn’t really play well at the last championship, kind of lost confidence a little bit,” Ryu said. “But I think it was great to have two weeks off, because when you have two weeks off you totally forget about how you played the last few tournaments.”

Local favorite Stacy Lewis and Moriya Jutanugarn were tied for second. They each shot 65.

“I think I go try to play a round like I have the last couple of days, really,” Lewis said. “That’s all I can do, and then hope for some help.”

First-round leader Park Sung-hyun followed her opening 63 with a 73 to drop into a tie for 10th at 6 under. Defending champion Lydia Ko was 5 under after a 67.

A day after opening with a 65 in gusty afternoon conditions, Ryu preyed on the Pinnacle Country Club course on a calm Saturday morning.

She needed only 25 putts, posting a 30 on her opening nine holes before closing out the blistering round with three birdies on her final four holes. Ryu capped the round with an uphill 10-foot birdie putt on the par-4 nine, much to the delight of the gallery.

She also earned the praise of Ai Miyazato, the retiring Japanese star who finished a group ahead of Ryu and was nearby at the scorer‘s tent as the South Korean walked off the course.

“Way to go, So-yeon,” Miyazato said. “You were on fire out there.”

The previous course record was 62, set by Angela Park and Jane Park in 2008 and matched last year by Ko and Ayako Uehara. Ko went on to win the tournament with a record score of 17 under.

Ko and Morgan Pressel held the previous 36-hole best at 14 under, set last year.

Ryu nearly won the tournament in 2013, losing playoff to Park In-bee.

She’s trying to win her fourth LPGA Tour title.

“I have a few good memories out here,” Ryu said. “Maybe losing in a playoff is not a good memory, but you know, close to a win. I think a lot of positive out there, so hopefully I can catch my opportunity tomorrow.” (AP)