Australia's Minjee Lee and American Alison Lee are on track for another Sunday showdown as they chase the biggest cheque in women's golf at the LPGA Tour's season-ending championship in Florida.

The in-form pair have waged some ding-dong battles of late and are again in the mix in a crowded leaderboard following the second round of the CME Group Tour Championship at Tiburon Golf Club in Naples.

American Lee, who won the Aramco Team Series event in Riyadh late last month, carded an eight-under-ar 64, after starting with a bang with five birdies in seven holes.

She then finished with birdies on four of her last five holes to sit in a tie at the top with first round co-leader Nasa Hataoka of Japan.

Hataoka atoned for missing a short par putt by closing with a pair of birdies, finishing with a 25-footer on the last hole.

Australian Lee, who beat her namesake in a playoff for the BMW Ladies Championship in South Korea a month ago, backed up her opening 64 with a 67 to be one stroke back at 13 under, her lowest 36-hole total at the event since 2015.

She is in a tie for third with China's Ruoning Yin and Amy Yang of South Korea, who had the best round of the day with a 63.

Australia's world No.5 picked up three birdies against one bogey on the front nine and after a bogey on the par-3 16th, finished with a flourish with two birdies.

A third victory from her past four starts would earn the 27-year-old the biggest purse in women's golf, a cheque for $US2 million ($A3.1 million).

Grace Kim is the next best-placed Australian, in a tie for 16th, after rounds of 69 and 68 while Hannah Green (70, 69) is in a group sharing 33rd spot.

Sarah Kemp added another 71 while Steph Kyriacou (73, 71) is in a tie for 55th to round out the Australian challenge.

American Lee, who is ranked world No.27, said she felt in tune with her game amidst a late-season surge to chase her first win in nine years on the LPGA Tour.

"I don't know why but I just feel really good about my game right now," the 28-year-old Californian said.

"My swing's in a really good place and I'm making a lot of really good putts - I wish I knew the recipe for success but I'm just trying my best to ride the wave right now because I feel like I'm playing great golf so hopefully it can continue through the weekend."

The elite 60-player Florida field features all the 2023 major winners chasing an $A11 million purse.

World No.2 Yin, the 21-year-old who won the KPMG Women's PGA Championship in June, and France's Celine Boutier are the only players mathematically alive to deny world No.1 and two-time major winner Lilia Vu from winning the LPGA Player-of-the-Year award.

Yin, who shared the lead after her opening round 63, followed up with a 68 while Boutier looks out of contention in a tie for 33rd after a second round 70.

American Vu, the double major winner this year, improved on her first round score of 70 with a 66 to share 10th place.