The Australian superstar defied more brutal conditions with a sublime third-round three-under-par 69 to skip out to a four-shot lead at PGA Frisco's scorching and windswept Fields Ranch East course.
Lee started the day three shots behind world No.2 Jeeno Thitikul and was unable to make any inroads on the Thai before hitting top gear around the turn.
Beautiful off the tee and with the broomstick in hand, the Perth prodigy collected her first birdie of the day on the ninth hole, then nabbed two more on 14 and 15 to turn a three-shot deficit into a four-stroke buffer.
After hitting 11 of 14 fairways and needing just 26 putts, Lee finished round three at six under after posting the only bogey-free round of the championship.
"I'm feeling pretty good," she said.
"I played really well within myself today. Took the birdies when I could and made really great up and downs when I was out of position.
"So, yeah, I'm going to try and stick to the same game plan and get it over the line tomorrow."
Thitikul briefly reached six under herself before stumbling with four back-nine bogeys in a rough four-over round of 76.
The leading duo are the only players in red numbers as the season's third major shapes as a Sunday match-play showdown.
South Korean Hye-Jin Choi (72), Japan's Miyu Yamashita (73) and American Lexi Thompson (75) are tied for third at one over, seven shots behind the runaway leader.
"Obviously major Sunday is a different story," Lee said.
"This is round three, so I have to still dig deep and post a score even with a four-shot lead.
"So I'm just going to put my head down and just work on the things that I can do and do it to the best of my ability.
"That's what I'm going to focus on."
Even Thitikul was in awe of Lee's performance.
"Three under par today, I was like, wow, that's really impressive," said the former world No.1.
"She played absolutely A-game for sure."
Victory for Lee would earn the 29-year-old the third leg of the women's golf grand slam following her 2021 Evian Championship triumph and 2022 US Open success.
Lee is also hoping to snap a 19-month winless run, the longest drought of her decorated career.
Victory would also secure Australian women's sport's highest earner another monster cheque of $US1.8 million ($A2.8 million), the equal-highest pay day in her game's history.
Perhaps most gratifying of all, the West Australian can bury the demons  from last year's spectacular final-round car crash at the US Open.
Lee opened up a three-stroke back-nine lead only to collapse down the stretch to finish tied for ninth.
If she does atone, Lee will likely endure another long day at the office after Saturday's round took some six hours.
The one-time world No.2 is happy to be playing in the final group once again with the bubbly Thitikul.
"Jeeno is great," Lee said.
"She's fast. She has good chat when we are waiting. We had a nice little chat.
"I've played with her a bunch of times already, so, yep."
World No.1 Nelly Korda will start the final round eight shots back in a share of sixth after shooting a 72.
Australian Grace Kim is a further shot back at three over after firing a brilliant 66, the low third round, to surge up the leaderboard.
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