Suzann Pettersen fired a course-record 9-under 63 on Friday to grab a 1-stroke lead after the opening round of the LPGA KEB - HanaBank Championship.
Pettersen, the 2007 winner, posted her low round of the year on the Ocean Course at Sky 72 Golf Club.
Karin Sjodin is one stroke back at minus-8, while Ai Miyazato, Hyun-Hee Moon, Ha Neul Kim, So Yeon Ryu and Azahara Munoz share third place at 6-under 66.
Defending champion and world No. 1 Yani Tseng is alone in eighth place after opening with a 67. That was just her second score in the 60s in her last 16 rounds.
Pettersen played the back nine first on Friday and got going with birdies on her first two holes. After a par on No. 12, Pettersen caught fire.
She converted a birdie chance on the par-5 13th and followed with birdies at 14 and 15 to jump to minus-5. Pettersen continued her blistering play with a birdie on the 17th.
"Got off to a good start, had the feel of the greens this morning, worked really hard to kind of feel the speed yesterday and made some great putts and obviously some great shots," Pettersen said.
After turning at 6-under, Pettersen remained hot. She birdied the second and made it two in a row with another birdie on the third.
Pettersen moved to 9-under as she birdied the par-5 fifth. With four holes left, including another par-5, Pettersen had an outside shot at shooting 59.
However, she parred the final four holes to end there.
"It feels like this year hasn't been a great year, but I feel like I've been playing well even though my scores haven't shown as good as I wanted to, but you can't stress that in this game," stated Pettersen, who has three top-10 finishes all season.
"You will go through ups and downs, and I wouldn't say I've been on a down, either, because I've been healthy, I've been feeling well and able to put in all the time and effort I feel is needed for my game. Maybe this can be a great turnaround."
Sjodin also started on the back nine and she had set a new course record before Pettersen beat her by one. Sjodin got on the board with a birdie on the 11th and came back with another on No. 13.
The Swede birdied 15 and 17 to move to minus-4. She parred three in a row around the turn.
Sjodin dropped in back-to-back birdie chances from the third. She birdied the sixth and again made it two in a row as she birdied the seventh. Sjodin parred the final two holes to end at minus-8.
"I was hitting the ball really solid, but maybe not very straight at all times. The birdies I made were long putts. I hit it close three times and missed all three," Sjodin admitted. "It seems to be a good idea to hit it far away and make long putts."
NOTES: Tseng, Soo-Jin Yang and Yeon-Ju Jung set the old course record of 65 last year...Pettersen also set the course record in Malaysia last week with her second-round 64...Players, caddies and rules officials all donned stickers to honor rules official Doug Brecht, who passed away last week due to complications from West Nile Virus.