Stanford and Miyazato, who shot four-under 68 Friday, both finished 36 holes at 11-under 133 and two clear of the field at Hillsdale Golf and Country Club.
Miyazato, the former No. 1 player in the world, is chasing her eighth win and second in four events, while Stanford, a four-time Solheim Cup participant and four-time LPGA Tour titlist, is after her first win since 2009.
For Stanford, who had seven birdies and a bogey Saturday, it is her ninth 36- hole lead and second of the year. She's gone on to win three of the eight previous times, including her last victory at the SBS Open at Turtle Bay.
"I guess I just had some better chances on the back (nine)," said Stanford, who finished her final nine holes at five-under 31. "A couple par-fives that you have good chances, but I was just trying to hit good shots and give myself opportunities, and the putter's rolling so that's good."
Miyazato, meanwhile, has won the last two times she led at the 36-hole mark.
"My confidence is back, and I'm really comfortable with my game right now," Miyazato said. "So I'm playing very good. I'm really satisfied about my game today."
Song-Hee Kim (68) is alone in third at nine-under 135, while defending champion Michelle Wie (69) headlines a group of eight players knotted in fourth at minus-eight. Seon Hwa Lee is among the eight at eight-under after posting the best round of the day at seven-under 65.
Friday marked the end of Sherri Steinhauer's long career after she missed the cut at six-over. The 48-year-old, who played in four Solheim Cups and won two major championships, finished with eight LPGA Tour wins and went out in style with a round of one-under 71.
"It's been a great run," said Steinhauer, who made her LPGA Tour debut in 1986. "Golf has been so good to me, the LPGA has been great to me, and to finish on the last hole and have a lot of the players and caddies back there was really special."
Steinhauer, whose first win came at the du Maurier Classic in Winnipeg in 1992, will serve as the assistant captain for Team USA at the Solheim Cup next month.
Stanford stole the show on Friday, starting out slow before coming on strong at the end.
Her first nine holes were rather unremarkable, with birdies at Nos. 2 and 6 and a bogey at No. 9 that left her at six-under, well off the lead; however, Stanford caught fire with a back-nine 31, good for five-under par during the stretch.
She had back-to-back birdies from the 10th and did the same from the 13th for four total in a five-hole span. After two pars, Stanford's final birdie came at the 17th before a two-putt par at the 18th ensured a spot atop the leaderboard.
"I feel good about my putter," Stanford said. "I think any time you feel good about your putter, it's probably better than feeling good about anything else. So I haven't had this feeling in awhile, so it's a lot of fun."
Miyazato also needed a strong finish to remain on top.
She began on the back nine and had two straight birdies from the 14th before a bogey at the 16th put her at eight-under around the turn. She had six straight pars from the 17th before three birdies in a four-hole stretch from the fifth got her to minus-11 and the lead before Stanford tied her.
"In the beginning of the round I was a little bit too tough on myself," Miyazato admitted. "So it was a little hard to make a gain. But I realized I'm too tough on myself. I just had a nice self-talk and I got really patient. So that's why I got a really good bounce back towards the end, so I'm very happy."
First-round co-leader Pernilla Lindberg managed only a one-under 71, but it was enough to join the large group at eight-under. The others included Gerina Piller, Becky Morgan, Brittany Lincicome, Paula Creamer and Sophie Gustafson.
Canadian Samantha Richdale, who entered the day in third place, stumbled to a one-over 73 and shares 20th at minus-five.
NOTES: A total of 78 players made the cut, which fell at one-under 143...A total of 105 players shot even-par or better on Friday...World No. 1 Yani Tseng shot her second straight 71 and is tied for 46th at two-under 142.