Inbee Park led at the halfway stage of the Manulife Financial LPGA Classic after a second-round 64 at the Grey Silo course in Ontario.
The Korean made eight birdies against a solitary bogey to move to nine under par and take a one-stroke lead ahead of compatriot Seo Hee-kyung, American Brittany Lang and China's Shanshan Feng.
Lang twice made three successive birdies in a six-under-par 65, world number four Feng made a tidy 68 and Seo was only denied top spot by a double bogey at the 17th hole.
Park told the LPGA Tour website: "I played great today. I hit the ball very well and especially hit my short irons really good, so gave a lot of opportunities and obviously putted very good today."
A large group at seven under featured Koreans Ryu So-yeon, Chella Choi and Yoo Sun-young, Americans Lexi Thompson, Katie Futcher and first-round leader Sandra Changkiwa and Sweden's Karin Sjodin.
England's Jodi Ewart led the British challenge at six under, alongside Swede Anna Nordqvist and American Stacy Lewis, while Paula Creamer and Suzann Petterson were the big names in a group at five under and Karen Stupples and Christel Boeljon were four under.
Christina Kim, Caroline Hedwall, Ai Miyazato and Britons Janice Moodie and Becky Morgan were among the notable players outside the cut line when play was suspended due to darkness. Seven players had still to complete their rounds, none of whom were likely to affect the mark of one over par.
Collated second-round scores and totals, Grey Silo Golf Course, Waterloo, Ontario, Canada
Note: Play has been suspended due to bad weather.
(USA unless stated, par 71):
133 Inbee Park (Kor) 69 64
134 Hee Kyung Seo (Kor) 66 68, Brittany Lang (USA) 69 65, Shanshan Feng (Chn) 66 68
135 So yeon Ryu (Kor) 70 65, Sandra Changkija (USA) 63 72, Sun Young Yoo (Kor) 68 67, Chella Choi (Kor) 69 66, Lexi Thompson (USA) 66 69, Karin Sjodin (Swe) 67 68, Katie Futcher (USA) 68 67
136 Anna Nordqvist (Swe) 64 72, Jodi Ewart (Eng) 68 68, Stacy Lewis (USA) 72 64
137 Paula Creamer (USA) 69 68, Nicole Hage (USA) 72 65, Suzann Pettersen (Nor) 67 70, Mi Jung Hur (Kor) 69 68, Kris Tamulis (USA) 70 67
138 Jennifer Song (USA) 71 67, Seon Hwa Lee (Kor) 68 70, Karen Stupples (Eng) 70 68, Angela Stanford (USA) 67 71, Amy Yang (Kor) 68 70, Jennifer Johnson (USA) 69 69, Jeong Jang (Kor) 70 68
139 Jennifer Rosales (Phi) 71 68, Jenny Suh (USA) 69 70, In Kyung Kim (Kor) 70 69, Jin young Pak (Kor) 69 70, Laura Diaz (USA) 69 70, Christel Boeljon (Ned) 71 68, Karlin Beck (USA) 66 73, Jacqui Concolino (USA) 69 70
140 Karrie Webb (Aus) 75 65, Beatriz Recari (Spa) 70 70, Sandra Gal (Ger) 72 68, Candie Kung (Tai) 68 72, Karine Icher (Fra) 72 68, Vicky Hurst (USA) 74 66, Michelle Wie (USA) 70 70, Min seo Kwak (Kor) 68 72, Hee Young Park (Kor) 71 69
141 Ayaka Kaneko (USA) 73 68, Il-hee Lee (Kor) 70 71, Maude-Aime Leblanc (Fra) 73 68, Morgan Pressel (USA) 70 71, Anna Grzebien (USA) 70 71, Stephanie Louden (USA) 70 71, Pornanong Phatlum (Tha) 71 70, Momoko Ueda (Jpn) 68 73, Jennie Lee (USA) 72 69, Victoria Tanco (USA) 76 65, Isabelle Beisiegel (USA) 71 70
142 Meena Lee (Kor) 74 68, Reilley Rankin (USA) 70 72, Kristy McPherson (USA) 70 72, Julieta Granada (Par) 70 72, Jee Young Lee (Kor) 71 71, Angela Oh (USA) 74 68, Na Yeon Choi (Kor) 72 70, Maria Hernandez (Spa) 70 72, Danielle Kang (USA) 69 73, Hanna Kang (Kor) 71 71, Mina Harigae (USA) 72 70
143 Rebecca Lee-bentham (Can) 72 71, Lorie Kane (Can) 71 72, Sarah-jane Smith (Aus) 70 73, Dori Carter (USA) 71 72, Leta Lindley (USA) 75 68, Belen Mozo (Spa) 73 70, Meaghan Francella (USA) 71 72, Alena Sharp (Can) 73 70, Katherine Hull (Aus) 70 73, Lacey Agnew (USA) 67 76
144 Stacy Prammanasudh (USA) 73 71, Azahara Munoz (Spa) 76 68, Mi hyang Lee (Kor) 72 72, Beth Bader (USA) 74 70, Hee-Won Han (Kor) 75 69, Haeji Kang (Kor) 74 70, Valentine Derrey (Fra) 70 74, Pat Hurst (USA) 68 76, Jane Rah (USA) 71 73, Numa Gulyanamitta (Tha) 72 72, Jenny Shin (USA) 72 72, Tzu-chi Lin (Tai) 76 68, Pernilla Lindberg (Swe) 74 70, Janice Moodie (Sco) 71 73
145 Ryann O'toole (USA) 71 74, Na On Min (Jpn) 76 69, Tiffany Joh (USA) 73 72, Jennifer Gleason (USA) 74 71, Meredith Duncan (USA) 74 71, Gerina Piller (USA) 74 71, Hannah Yun (USA) 70 75, Elisa Serramia (Spa) 74 71, Becky Morgan (Wal) 73 72, Dewi Claire Schreefel (USA) 74 71, Moira Dunn (USA) 69 76, Alison Walshe (USA) 72 73
146 Giulia Sergas (Ita) 75 71, Jane Park (USA) 73 73, Sydnee Michaels (USA) 76 70, Paige Mackenzie (USA) 74 72, Mo Martin (USA) 73 73, Christina Kim (USA) 77 69
147 Mariajo Uribe (Col) 75 72, Caroline Hedwall (Swe) 71 76, Amy Hung (Tai) 70 77, Diana D'Alessio (USA) 71 76
148 Nannette Hill (USA) 76 72, Ji-Young Oh (Kor) 72 76, Irene Cho (USA) 74 74, Kathleen Ekey (USA) 75 73, Wendy Ward (USA) 72 76, Amelia Lewis (USA) 76 72, Amanda Blumenherst (USA) 73 75
149 Ai Miyazato (Jpn) 74 75, Mitsuki Katahira (Jpn) 75 74, Sophie Gustafson (Swe) 77 72, Christine Song (USA) 76 73
150 Kristen Park (USA) 73 77, Veronica Felibert (USA) 74 76, Kirby Dreher (Can) 76 74, Cindy Lacrosse (USA) 75 75, Stephanie Kono (USA) 74 76, Stephanie Sherlock (Can) 75 75
151 Yoo kyeong Kim (Kor) 75 76, Samantha Richdale (USA) 77 74
152 Ashli Bunch (USA) 75 77
153 Tanya Dergal (USA) 77 76
156 Wendy Doolan (Aus) 78 78
162 Lindsey Smith (Can) 80 82
