Mi Hyun Kim survived the windy conditions to shoot a 69 -- the only sub-70 round posted on Friday. The diminutive Korean finished tied for second at four-under 140 with Jane Crafter of Australia, who shot 71.
Juli Inkster, the winner here in 1999 and 2000, birdied three holes on the back nine for a 70 that lifted her into fourth place at minus-two.
On a tough day made even more difficult by tricky pin positions, Kerr hit 16 of 18 greens but took 34 putts, eight more than she needed in her opening 66.
'I hit a couple par-fives in two but had some three-putts for par, that's the only change I could have made to improve,' said Kerr. 'It was tough today, really windy, a lot of in between clubs, but I hit really good shots.'
Kerr birdied her first and last holes of the day, both after nine-irons to about four feet. Her two bogeys came on par-threes on her inward nine.
Kerr, 24, is still without a victory in six years on the LPGA Tour. She has racked up 19 top-10 finishes during her career, including a pair of third- place showings this year.
'I've been in this position a number of times, and in the recent past I haven't been as comfortable,' she admitted. 'I want to be one of the top players, if not the top player. You have to be comfortable out there, and at peace with yourself.'
Kim, the 1999 LPGA Rookie of the Year, was one-under for the day with three birdies and two bogeys through 14 holes. She closed with two birdies over her last four holes, the first set up by a seven-wood to 20 feet at the 15th and the next with a six-iron to 12 feet at the 18th.
'Most of the front nine was very windy, but not so much on the back nine,' said Kim, 25. 'No changes tomorrow, just play the same and hope for less wind.'
The 46-year-old Crafter, who has one win on the LPGA Tour and three others in Australia, bogeyed her first two holes but bounced back with a 35-foot birdie putt at the third and a six-footer at the fourth.
She slipped back over par at the par-three eighth when her 11-wood tee shot found a bunker and she failed to get up and down to save par. She negated the bogey with a wedge to three feet for birdie at the 12th, then broke into red figures by holing a 20-foot birdie putt at the 14th.
First-round co-leader Sara Sanders struggled to a five-over 77 in her second trip around Twelve Bridges. She fell into a tie for fifth place at one-under 143 with Julie Piers, Mhairi McKay, Heather Bowie and defending champion Se Ri Pak.
'Everything is fine, except my putting,' said Pak, who captured the 14th LPGA title of her career two weeks ago in Los Angeles. 'I still have two days left. I just have to be a little more aggressive now.'
The 36-hole cut came at seven-over 151 and included 74 players.
Full field scores from the Longs Drugs Challenge