World number one Jeeno Thitikul set a 54-hole tournament record at the CME Group Tour Championship as she extended her lead to six shots.
Thailand’s Thitikul fired an eight-under-par 64 in her third round to move 22 under overall.
“It has been pretty good,” said 22-year-old Thitikul, who won this title last year at 22 under.
“I was just trying to focus on myself and trying to make birdies and birdies and birdies because I know there’s a bunch of players who will be able to make some more birdies.”
Thitikul’s compatriot Pajaree Anannarukarn and world number two Nelly Korda both shot 65 on Saturday and are joint second.
Thitikul, who led by three stokes at the halfway stage, bogeyed her first hole on Saturday.
But she then birdied the second, fourth, fifth and sixth holes, following up on the back nine with four birdies in a row from the 11th to the 15th – and another on the 17th.
Victory would make Thitikul the second woman – after South Korea’s Ko Jin-young in 2020 and 2021 – to win the tournament in successive years.
She would also receive $4m (£3.1m) in prize money from a total pot of $11m (£8.4m).