Kim is in a position to overtake fellow South Korean Inbee Park for the season money title -13 Kim Sei-young (Kor); -12 Ko Jin-young (Kor); -10 Hall (Eng); -9 Ernst (US), Thompson (US), Hull (Eng), Lee (Aus), Henderson (Can) Full Classification
Number two in the world Kim Sei-young made six birdies to take a one-time lead over the best Ko Jin-young in the CME Group Tour Championship in Florida.
Kim, looking for a second straight win in the season-ending event in Naples, finished 13 under par after taking a shot off the lead on day three .
England's Georgia Hall bounced back from her lone bogey on fifth with five birdies in a four-under 68, leaving three shots behind the leader.
Countryman Charley Hull shares fourth place.
Hull is one shot back, along with Canadian Brooke Henderson, Australian Minjee Lee and Americans Austin Ernst and Lexi Thompson.
"Well, my position is really good. I have a chance to chase it all," said Kim, whose two victories since the LPGA's coronavirus shutdown include her first major in the PGA Women's Championship.
"If I play well tomorrow, I have a good chance."