Michele Redman stands one stroke back at 6-under after a 70, while Denise Killeen, Karen Weiss and Rachel Teske are another three shots off the pace at minus three.
Because Friday's play was washed away due to rain, Annika Sorenstam will have just one more round to fight for her fifth straight win of the season. She was seven strokes back to begin the day but lost ground with an even-par 72.
Things weren't smooth sailing early for Pak, who drove left into a bad lie at the par-4 1st hole and had to punch out with her second shot. Although it looked as if she recovered well with a wedge to eight feet, Pak missed the par-saving putt and posted her first bogey of the tournament.
Pak dropped to 4-under after playing the par-3 4th, where she hit a 7-iron to the green then three-putted from 25 feet.
After being stuck in neutral with pars over the next 10 holes, Pak broke out of her scoring slump at the 15th with a 6-iron to six feet for a birdie. She birdied the next two holes as well, rolling in an eight-footer at No. 16 followed by a four-footer at No. 17.
'I had almost a bad day, but had a strong finish,' said Pak, who is seeking her second victory of the year after winning the season-opening event in Orlando. 'So I'm in pretty good shape. I just missed one green today and missed one fairway.'
Redman, who with a win this week would become the first American-born player to triumph on the tour this season, experienced an up-and-down start to her round Saturday with a birdie and two bogeys over the first five holes.
She birdied the first two holes of the back nine with putts of six and 12 feet, respectively, then knocked a 9-iron to eight feet for her last birdie of the day.
'The day off yesterday really helped me,' said Redman, the winner of last year's Betsy King Classic. 'The pins were difficult today, but I stayed relaxed and continued to hit the ball well.'
Killeen, whose best finish in 10 years on the LPGA Tour was a tie for sixth at the 1996 ShopRite Classic, collected seven birdies and four bogeys for a 69. Also looking for her first title is Weiss, who had a 71, while Teske, a three-time winner, shot 72 on Saturday.
Rosie Jones and two-time defending champion Juli Inkster each shot 68s to share the honor of low round of the day. Jones is tied for sixth at 2-under, while Inkster improved on her opening 79 to climb from 130th into a tie for 38th at 3-over par.
Sorenstam, who came from an LPGA record-setting 10 strokes back to win last week's event in Los Angeles, will need to make up a mere eight shots this Sunday. She is one of nine players at 1-over 145.
'I just need to get off to a good start and keep it going through the entire round,' Sorenstam said. 'Maybe then I can put pressure on the leaders. But I know Michele is up there and she is hungry for a win. And Se Ri, shes already won this season, so maybe she wont feel that much pressure.'
Sorenstam's sister, Charlotta, aced the 137-yard 4th hole with a 6-iron. She finished round two with a 71 and a share of 27th at plus-two.
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