Tour Championship: Kim Sei-young takes control as Georgia Hall slips
|CME Group Tour Championship: Second-round leaderboard|
|-12 Kim (Kor); -10 Masson (Ger); -9 Korda (USA), Henderson (Can); -8 Oh (Aus); -7 Y Liu (Chn), J Korda (US), L Thompson (US)|
|Selected others: -6 Hall (Eng), Ewart Shadoff (Eng); -5 Hull (Eng), B Law (Eng)|
Kim Sei-young shot a second-round five under 67 to hold a two-shot lead at the halfway stage of the LPGA's season-ending Tour Championship.
The South Korean carded six birdies and a bogey to move to 12 under and stay in contention for a 10th LPGA win.
Germany's Caroline Masson is second after shooting a six-under 66 to climb the leaderboard.
England's Georgia Hall, who had made a strong start in Florida, dropped down the order after a one-over 71.
The 2018 Women's British Open winner carded a five-under 67 in the first round to sit within two shots of the lead but is now tied for ninth, six shots off Kim.
There were better fortunes for Hall's compatriot Jodi Ewart Shadoff, who shot a seven-under 65 to move into a share of ninth alongside Hall and one ahead of fellow Englishwomen Charley Hull and Bronte Law.