The American carded a 2-under 70 on Saturday (Sunday AEST), but dropped two shots during her round after starting with four birdies across her first six holes.
Cassie Porter is the best-placed Australian and is 13 shots back from Korda and in a tie for 20th.
Hannah Green is one shot back at two-under and shares 29th place heading into the final round of the LPGA Major.
Despite her lead, their is work for Korda still to do, even though at times she looked close to unbeatable with another clinic controlling her irons on the heavily sloped greens of Memorial Park.
And then the gap began to shrink as her contenders did just enough to stay in range.
"I played really solid on the front and then just kind of ... not may have lost concentration, but the wind started picking up and then I just put myself into great positions (and) didn't kind of execute really well," Korda said.
The heat and humidity also took a toll, and Korda often walked the fairways with an umbrella to shield her from the sun.
Patty Tavatanakit, who went 48 holes without a bogey before making one on the 13th, bounced back with a pair of birdies over the last five holes for a 69 to get within five shots.
It was a remarkable scrambling performance for Tavatanakit, who won this major as a rookie in 2021. She got up-and-down seven times, missing out only on the 13th.
Ruoning Yin of China, a Women's PGA champion and former No.1 in the world, shot 66 and was six shots behind along with Pauline Roussin-Bouchard of France, who had a 67.
"I just don't really make mistakes and I've been hitting well and putting well," Yin said. "Everything is going the right direction."
Korda's 16-under 200 through three rounds ties the tournament record set by Jennifer Kupcho in 2022, the last year the major was at Mission Hills in the California desert.
Minjee Lee shot a 71 on Saturday to be at one-over for the tournament.
Fellow Australian Karis Davidson is also in a share of 54th with Lee, after she carded a 74 in round three.
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