Her total of 15-under-par 201 set a new 54-hole record for this elite-field event, bettering the old mark of 202 established by Nancy Scranton and Sherri Steinhauer last year.
Pak, who turned 24 on Friday, tallied 10 birdies against two bogeys for a 64 that tied the 18-hole tournament record set by Maria Hjorth in 1999 and matched by Steinhauer in 2000.
Click Here to See Se Ri Pak's Scorecard.
Lorie Kane of Canada shot a 5-under 67 for second place at 8-under 208, while Dottie Pepper, the winner of this event in its inaugural year of 1994, turned in a 69 for a share of third place at 7-under with Grace Park, who had a 71.
Defending champion Karrie Webb carded a 69 to tie Wendy Doolan (68), Meg Mallon (72) and Emilee Klein (73) for fifth at minus-four.
Mi Hyun Kim, the leader after the first two rounds with scores of 65 and 71, struggled to a 6-over 78 Saturday and fell into a tie for 12th place at 2-under-par 214.
The AFLAC Champions features a 40-player field of tournament winners from the past three seasons and active LPGA Tour Hall of Famers.
Click here for Full-Field Scores from the AFLAC Champions Presented by Southern Living