Minjee Lee has climbed the leaderboard to remain in the mix for the biggest cheque in women's golf's history.
Lee's 5-under-par 67 in the second round vaulted Australia's world number four into a tie for fifth at the halfway point of the $17 million Tour Championship in Naples, Florida.
She is five shots off the pace, with world number one and defending champion Jeeno Thitikul firing a dazzling 9-under 63 to seize a commanding three-shot lead over South Korean Sei Young Kim.
Thai Thitikul won last year's Tour Championship with a 22-under total and remains on track to eclipse that score.
Surging to 14-under, Thitikul was bogey free on Saturday AEDT after being three shots behind Somi Lee following the first round.
Kim, the 2019 winner, is again in the hunt for a second season-ending championship after moving to 11-under with a second-round 66.
South Korean's Lee (69) and Japan's Nasa Hataoka (67) share third place a further shot back at 10-under.
On a star-studded leaderboard, Australia's Lee is tied at 9-under with US world number two Nelly Korda (64), Canadian Brooke Henderson (67) and Thailand's Pajaree Anannarukarn (67).
Three-time major winner Lee was only a shot back after negotiating the front nine in 4-under.
But she could only manage one more birdie on the back nine in an otherwise blemish-free round.
"I had a pretty nice start," Lee said.
"Four birdies on the front and then one birdie on the back. But I feel like I'm going pretty steady out there. For the most part it was pretty solid.
"Just going to try and clean up my shots a little bit and hope for a really great weekend."
Lee looks like Australia's only weekend contender after Grace Kim and Steph Kyriacou both fell off the pace with even-par rounds of 72.
Kim and Kyriacou both started round two tied with Lee in seventh spot at 4-under but have slumped to joint 27th place on the leaderboard.
At 3-over following a second-round 71, fellow Australian Hannah Green is last in the 60-player field.
AAP