(AFP) - Chella Choi Woon Jung fired a six-under 66 to take a one-stroke lead after the first round of the Manulife LPGA Classic on Thursday.
The South Korean reeled off seven birdies and only one bogey to tame the demanding Whistle Bear Golf Club lay-out at Cambridge, Ontario.
Choi was pursued by America's Brittany Lang, Sweden's Dani Holmqvist, Spaniard Azahara Munoz and fellow Korean Chun In Gee, who were one off the lead.
The 26-year-old Choi said she was happy with the way she had mastered blustery conditions.
"A lot of wind today, but my game is good and driving is good, shot was good, so I made a lot of birdies," said Choi, who tied for seventh at the Canadian Pacific Women's Open in Calgary last weekend.
"I worked really hard the last three weeks. So I want to hit straight and strong, my drive four days, so I focus on just my driving four days. ... My driving is better, so the game is easier than before."
Choi, who has only one LPGA title to her name, is aiming to go one better than in 2012 at the Manulife, where she lost in a play-off with Lang and two other South Korean players, Park In Bee and Seo Hee Kyung, when the tournament was held at Grey Silo in Waterloo.
Lang meanwhile revelled in being back on familiar territory in Ontario.
"I love coming up here," she said.
"I love everything about it... I just feel super comfortable here."
American Brittany Lincicome, Taiwan's Hsu Wei-ling and Japan's Ai Miyazato were among a group of 11 players two off the lead after carding four-under 68s. Defending champion Suzann Pettersen of Norway is in a group of 17 players tied for 17th at 69.
World No. 1 Lydia Ko of New Zealand was four off the pace after shooting a two-under 70. In-form Thai star Ariya Jutanugarn was also four back.
Ariya started her round with a hat-trick of birdies in her first three holes, only for her momentum to stall with two bogeys on the back nine.