There was a one-hour rain delay as a storm came through Kingsmill Resort & Spa in the late afternoon. All players were able to complete two rounds and the cut was made on Friday.
Patricia Meunier-Lebouc, who won the season's first major at the Nabisco Championship, and Cristie Kerr shot matching rounds of 3-under 68 and are tied for fifth place at 5-under-par 137.
Annika Sorenstam posted a 1-under 70 on Friday and is part of a group at minus-4. Se Ri Pak (69), Jennifer Rosales (69), Mi-Hyun Kim (69) and Karen Stupples (70) joined Sorenstam in a tie for seventh.
Park began on the back nine at Kingsmill and promptly birdied her first hole when she knocked a 6-iron to 10 feet at the 10th. She hit a lob-wedge to three feet to set up birdie at the next hole but those birdies would be the last positives for Park on her first nine.
She missed the fairway at the par-5 15th and was forced to punch into the short grass. Park missed the green with her third shot and her chip to get on left her eight feet, where she missed the putt for par.
At the 18th, Park played an eight-iron onto the green but three-putted, when she missed four-footer for par. She went out at even-par 35 but the 24-year-old rebounded on her second nine.
Park sank a 10-foot birdie putt at the fourth then nearly holed a gap-wedge at the sixth. She settled for a tap-in birdie and almost holed another shot at nine. Her 7-iron narrowly missed going in but it was another kick-in birdie and a share of the 36-hole lead.
'The past two days have been up and down, a little roller-coaster ride,' said Park. 'Maybe I will go to Busch Gardens and do all of the rides and get it done there and get it over with. A lot of great shots, a couple of misses, a lot of great putts and lots of bad putts.'
Ochoa, who shot an opening-round 66 to share the lead, looked good at the start with a 10-foot birdie putt at the first. She knocked an 8-iron to six feet at the sixth to set up another birdie but that would be it for Ochoa's birdies on Friday.
The good news for Ochoa was that there would be no bogeys on her card either. She parred the last 12 holes, missing a few opportunities for birdie, but still took a piece of the 36-hole lead for the first time in her brief LPGA Tour career with her final-round 69.
'I'm extremely excited, but I think it's good, just to think about it,' said Ochoa, who was a standout at the University of Arizona. 'I have been in the lead before many times in college and in professional tournaments too. There is still 36 holes left, a lot of golf out there. Anything can happen and I am just very happy with my position trying to be calm and patient and wait for a good moment on a weekend and hopefully play good.'
LPGA Teaching and Club Professional member Suzy Whaley rebounded from a 6-over-par round of 77 on Thursday with a 2-over 73 on Friday. Whaley, who will be competing on the PGA Tour later this year at the Greater Hartford Open, missed the 36-hole cut, which fell at 5-over-par 147.
Among the other prominent names to miss the cut were Kelli Kuehne (148), Dottie Pepper (150) and Maria Hjorth (142).