England's Charley Hull and world No 1 Nelly Korda moved into contention at the CME Group Tour Championship in Florida, where Angel Yin holds a two-shot lead after the second round.
Korda and Hull were eight and nine strokes respectively behind then-leader An Na-Rin at the end of day one in Naples, with the former carding an even-par 72 and the latter a one-over 73.
But both registered six-under 66s on Friday, leaving Korda just four shots back on six under and Hull five adrift on five under.
Korda, chasing an eighth title of 2024 after beating Hull to win The ANNIKA last week, recorded a blemish-free round, with four birdies as well as an eagle at the par-four third.
Hull dropped one shot, at the par-three fifth, but made six birdies on her front nine and then another at 17 to sit just inside the top 10.
Yin, eyeing a first victory since the Buick LPGA Shanghai in October 2023, shot a three-under 69 to rise to 10 under for the event, with 18-hole leader An in second place alongside fellow South Korean Choi Hye-Jin on eight under after an even-par second round.
The winner of the LPGA Tour's season finale will pocket $4m (£3.2m) in prize money.
Speaking after her second round, Korda said: "Golf is just crazy. You go from playing so well last week to not being able to find the centre of the clubface yesterday.
"[That] always humbles you but that's what you love so much about it. I went to the range after my round yesterday and tried to find a different feel. I felt a little better out there today and hopefully I can keep progressing."
Watch round three of the CME Group Tour Championship, from Naples in Florida, live on Sky Sports Golf from 7pm on Saturday or stream with NOW. Final-round coverage then begins at 6pm on Sunday.
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