Jackie Gallagher-Smith, who was tied for second after the opening round, carded a 76 of her own to fall four shots back at 1-over-par 145. She was joined by Lorie Kane, Mi Hyun Kim and Mhairi McKay in a tie for third.
'I'm very unhappy,' said Pak, who is the only player under par after two rounds. 'I thought an even-par round would be good in such windy conditions, and for tomorrow, it's the same.'
After a first-round 65 at The Club at Nine Bridges, Pak was unable to build on her early success as cold conditions and strong winds plagued the course. She faltered with a bogey at the par-5 third but responded with her only birdie of the day at the par-4 fifth.
Pak found trouble again with a bogey at the par-3 seventh and stumbled with a double-bogey at the 14th. However, Pak's lead was never in question as her competitors were also unable to escape the difficult conditions.
Annika Sorenstam, who is trying to become the first player to win 10 events in a single season on the LPGA Tour since Kathy Whitworth in 1968, had three birdies on her round to go along with two bogeys and a double-bogey for a 73.
'It was very cold and windy,' said Sorenstam. 'It was one of the toughest conditions I played in a really long time.'
Meanwhile, Cristie Kerr, who was tied for second after round one, ballooned to 10-over par for the tournament after a round of 85.
Pak carried a four-shot lead with one hole to play but a bogey at the par-5 last shrunk her advantage to three.
The 25-year-old, who won the Mobile LPGA Tournament of Champions two weeks ago, is looking for her fifth victory of 2002.
Park had two bogeys on the front nine but collected three birdies on the inward half for a round of 71. The 23-year-old was the only player to shoot below par on Saturday.
'I told my caddie that it felt like I shot 64 out there,' said Park. 'Yesterday, I think I had a little bit of an alignment problem with my putting, but I got that straightened out, so that was very, very good for today.'
Sorenstam remains in contention after braving the elements. The Swede is five shots back at 2-over-par 146 alongside Danielle Ammaccapane and Carin Koch.
Catriona Matthew, Il Mi Chung and Joanne Morley share 10th place at 4-over-par 148.
This is the first year of the tournament. The event was scheduled to debut in 2001 but was cancelled following the recently initiated military action by the United States and its allies following the terrorist attacks of September 11th.
This is the first time an LPGA tournament has been held in Korea since 1997. The event is the first of three straight Asian tournaments on the LPGA Tour.
Full-field scores from the Sports Today Classic