Korda fired a second straight 65 to surge to 14 under par and a record-equalling six-shot halfway lead at Memorial Park Golf Club in Houston.
The American world No.2 bagged eight birdies to remain firmly on track for a second Chevron triumph in three years.
Korda's huge buffer matches the biggest halfway lead at a major in women's golf history, while no player has won this event from six strokes back through 36 holes since Morgan Pressel in 2007.
"I'm comfortable with my game," Korda said. "I think where I'm the most comfortable is definitely with my mindset of knowing when I mess up I'll figure it out.
"Sometimes I think you get stuck in wanting to play well and wanting to be at the top always that you have this tension of not wanting to make a mistake.
"I think there is a power in knowing it's OK to make a mistake and just bounce back."
Korda added she was hitting it in the spots where she wanted to and 'missing it into the spots that I want to'.
"If there is a tucked pin and it's kind of stupid, I would rather give myself a longer lag putt and give myself the best opportunity for par.
"That's kind of the way we been playing the past two days, not taking kind of stupid risks."
Korda's closest pursuer is Patty Tavatanakit, whose three-under 69 was the only bogey-free round of the day.
South Korean Ina Yoon (68), American Ryan O'Toole (68) and US amateur Farah O'Keefe (69) are tied for third at seven under.
Cassie Porter (70-72) is the leading Australian, in a share of 22nd spot at two under.
Karis Davidson (71-71) is one under and joint-31st after finishing her second round with a sour three-putt bogey.
Hannah Green and Minjee Lee both mounted spirited fightbacks to make the cut after both superstars looked set to miss the weekend action.
Green was three over for the tournament before rolling in three birdies in her last 10 holes in a second-round 71, putting her equal-36th at even par.
Still recovering from the illness that forced her withdrawal before last week's second round in LA, Lee also rallied from outside the cut line with a 72, leaving the triple major winner tied for 62nd at two over.
But Robyn Choi (73-75), Gabriela Ruffels (78-74), Grace Kim (75-77) and Steph Kyriacou (73-81) all missed the cut.