The two-stroke triumph over Sweden's Maja Stark stretched Korda's season win streak to five titles in five starts to equal the LPGA record set by American Nancy Lopez in 1978 and matched by Sweden's Annika Sorenstam from 2004/05.
Korda withstood a tension-packed back nine but never lost her lead in holding off rivals over the closing holes at Carlton Woods in suburban Houston to claim the $1.2 million (£968,800) top prize in the first women's major tournament of the season.
"I can finally breathe now. That back nine felt like the longest back nine of my entire life," Korda said.
"It was a little bit of a grind on the back nine but happy to get the win."
The 25-year-old American fired a three-under-par 69 in the final round to finish on 13-under 275 after 72 holes.
Stark was second on 277 after a closing 69 followed by American Lauren Coughlin and Canada's Brooke Henderson sharing third on 278 and South Korean Ryu Hae-ran fifth on 279 after closing on 74.
Korda, the daughter of former Czech tennis star Petr Korda, won her only prior major crown at the 2021 Women's PGA Championship while also capturing a gold medal at the Tokyo Olympics.
This year, Korda also won January's Drive On Championship, last month's Seri Pak and Ford championships and the LPGA Match Play earlier this month.
"There's a key in the simplicity that I have. I honestly take it a shot at a time," Korda said. "It has been working so far. I feel like sometimes golf can get overcomplicated."
There were plenty of late complications.
At 10, Korda missed the green with her approach but chipped in for birdie to reach 14-under and lead by four.
Korda went way right off the 11th tee on the way to her first bogey, trimming her lead to three over Ryu and Coughlin, who both closed the front nine with back-to-back birdies.
"I was definitely starting to feel it on the back nine, the nerves setting in," Korda said. "It's a major. It's everything I've always wanted as a little girl, to lift that major trophy.
"I can finally breathe now and enjoy the moment because I was definitely really nervous. I feel sick to my stomach."
Coughlin closed within two strokes with a birdie at the par-4 14th and Korda missed a five-foot birdie putt at the par-5 13th as tension built.
Coughlin, however, made bogeys at 16 and 17 and Henderson took a bogey at 14, leaving Korda with a four-stroke lead.
Korda, however, stumbled with a bogey at 15 and when Coughlin closed with a birdie and Stark birdied the par-3 17th, Korda's lead was again down to two.
After clutch pars at 16 and 17, Korda watched from the fairway at the par-5 18th as Stark came up a foot short on an eagle chip then tapped in for birdie, cutting Korda's lead to a single stroke.
Korda sent her second shot just over the green, missed an eagle putt but sank a short comeback birdie putt for the victory.
Early start for Korda
After a Saturday storm halted play and dumped 1.5 inches of overnight rain on the course, Korda made seven pars to close out her third round on 69 and share second with Henderson, one stroke behind Ryu, last year's LPGA Rookie of the Year.
The three went out in the last group for Sunday's final round and Korda quickly grabbed the lead.
Ryu opened with back-to-back bogeys to tumble from the top. Henderson answered a bogey at the second with a birdie at the third to stand on 10-under but Korda birdied the par-3 third from 15 feet and escaped a bunker to birdie the par-5 fourth for a two-stroke lead at 12-under.
Henderson answered a double bogey at the fourth with birdies at five and six while Korda sank a 14-foot birdie putt at the eighth, reaching 13-under and stretching her lead to three strokes at the turn.
