Jeong Jang shot a 4-under 68 and is alone in second place at minus-9. Defending champion Meg Mallon and 50-year-old Marilyn Lovander both carded rounds of 3-under 68 and are tied for third place at 8-under-par 205.
Han began Saturday's third round one shot behind Hall of Famer Beth Daniel, and the 27-year-old South Korean wasted little time in closing the gap.
Han hit an 8-iron to 6 feet to set up birdie at the first hole. She made it two in a row thanks to 7-iron tee shot at No. 2 that stopped 10 feet from the hole.
At the par-4 fourth, Han knocked an 8-iron to 4 feet to collect her third birdie in four holes and get to 9 under par for the championship. Things would slow down for Han after the birdie at four.
She made a couple of interesting par saves on the front nine, but it was mostly two-putt pars. In fact, Han parred her next 11 holes in a row, but remained in a tie for the lead with Jang.
At the par-4 16th, Han hit a 7-iron to 8 feet and finally holed a putt. She moved one stroke ahead of Jang, who was already in the clubhouse at minus-9.
Han laid up with her second shot at the par-5 closing hole at Highland Meadows, then knocked her third to 5 feet. She had to wait for several minutes while Daniel made a mess of the hole then needed a rules official for a drop.
When it was finally her turn, Han rolled in the birdie putt for her two-shot lead.
'I'm pretty happy,' admitted Han, who is a three-time winner on the LPGA Tour. 'I just want to play tomorrow, like today.'
Han will be playing with a familiar face in Sunday's final round. She played junior golf with Jang and the two are friends, often times playing practice rounds with her.
'We both know each other,' said Han. 'She's a good friend. We practice together, but do not play together much in tournaments. She's two years younger than me.'
Jang played great early on with a 20-foot birdie putt at the fourth. She rolled in another 20-footer for birdie at seven, then collected her second birdie in a row with a tap-in at the par-3 eighth.
Jang hit a 9-iron to 8 feet to set up birdie at the 12th. Once again, she posted back-to-back birdies as she holed a 15-foot birdie putt from the fringe at 13.
Trouble came at the par-3 14th when her 9-wood tee shot came up short. She three-putted for a bogey, but parred out to be within two shots of the lead.
'I'm pretty happy right now,' said Jang, who is winless on the LPGA Tour. 'I think I'll have too shoot a couple under par. I really want to try hard tomorrow.'
Leta Lindley shot a 3-under 68 and is alone in fifth place at minus-7.
U.S. Women's Open champion Birdie Kim posted an even-par 71 and is tied for sixth place with Becky Morgan (68), Sung Ah Yim (68) and Heather Bowie (69). The group is knotted at 6-under-par 207.
Daniel struggled badly on Saturday with a 2-over 73. She is tied for 10th place with Pat Hurst (67), Beth Bader (68) and Gloria Park (71) at 5-under-par 208.