SAN FRANCISCO, 26 Apr 2015 (AFP) - Henderson, who had seized the lead on Friday with a sizzling 65, had a 54-hole total of nine-under par 207 and a one-stroke lead over American Morgan Pressel and South Korea's Kwak Min-Seo.
Pressel carded a five-under 67, while Kwak posted a 69 for 208.
They were two strokes in front of world number one Lydia Ko of New Zealand, the first-round leader who posted a one-under 71 for 210.
Henderson, a 17-year-old seeking her first tour win after turning pro this year, stretched her lead to as many as five strokes, but faltered down the stretch.
She moved to 10-under with an opening birdie, but gave the shot back at the next hole. After a birdie at the par-five sixth, she reeled off seven straight pars before she got up and down for birdie at the par-five 14th.
Leading by three with four to play, she closed with back-to-back bogeys to see her lead dwindle to one heading into the final round.
"It was a great day out there. It was really tough conditions and I was able to play really well," Henderson said. "Couple of times my short game needed to bail me out, and it was able to do that, especially the first 16 holes.
"The last two, unfortunately I dropped two shots. Overall it was a great day and I'm really happy to be where I am."
Pressel surged up the leaderboard with a round that included six birdies -- four of them on her last six holes.
"I wouldn't say it was the absolute very best I could've played, but I certainly kept control of the golf ball in the wind," said Pressel, whose two LPGA tour wins include a major title at the 2007 Kraft Nabisco Championship. "It was a completely different golf course today. It was very interesting with all the rain overnight."
Kwak's round included four bogeys, five birdies and an eagle at the par-five ninth, where she holed out from the fairway.
Leading third-round scores on Saturday at the LPGA Tour's Swinging Skirts Classic (USA unless noted, par-72):
207 - Brooke Henderson 70-65-72
208 - Morgan Pressel 69-72-67, Kwak Min-Seo (KOR) 72-67-69
210 - Lydia Ko (NZL) 67-72-71
211 - Feng Shanshan (CHN) 70-70-71, Stacy Lewis 69-71-71
212 - Ryu So-Yeon (KOR) 73-68-71
213 - Kim Sei-Young (KOR) 74-69-70, Sandra Gal (GER) 74-67-72
214 - Anna Nordqvist (SWE) 70-74-70, Moriya Jutanugarn (THA) 70-72-72, Tiffany Joh 70-70-74, Julieta Granada (PAR) 70-69-75, Yueer Cindy Feng (CHN) 70-68-76
215 - P.K. Kongkraphan (THA) 68-76-71, Lee Mi-Rim (KOR) 74-68-73, Amy Yang (KOR) 72-68-75, Sakura Yokomine (JPN) 71-67-77, Choi Na-Yeon (KOR) 69-68-78