Top-ranked Lydia Ko bogeyed the 18th hole Saturday to cut her lead to one stroke heading into the final round of the KPMG Women's PGA Championship.
Seeking her third straight major title, Ko shot a 1-under 70 to reach 2 under. She won the Evian Championship in September in France for her first major title and took the ANA Inspiration in April in California.
Brittany Lincicome and Gerina Piller were tied for second. They each shot 71, with Lincicome also bogeying the 18th.
The 19-year-old Ko used her deft short-game to save shots on the 16th and 17th holes, but couldn't avoid dropping a shot at the last when her third shot went to the back of the green and she missed a 15-foot par putt.
Second round co-leaders Brooke Henderson and Mirim Lee each shot 73 to drop into the group at even par. Only three players were under par, but 13 were within three shots of the lead.