Chevron champ Saigo takes three-shot US Women's Open lead
Japan's Saigo, who won a five-way playoff to lift her first major trophy at the Chevron Championship, shrugged off a spectacular piece of bad luck to build a 36-hole total of 136 at Erin Hills.
Korda posted a five-under-par 67 to headline a group of six players on 139.
Saigo, 23, last year's LPGA Rookie of the Year, said her victory at the Chevron in April had given her new confidence but hadn't changed her fundamental approach.
"I think that I was able to be more confident about my judgments that I make," she said. "However, I would like to play my play rather than thinking about changing myself."
She teed off on 10 and gained ground quickly with birdies at 11 and 12, but needed all of her mental poise after disappointment at the par-five 14th, where her third shot hit the flagstick and bounced back into a bunker.
Instead of a birdie she ended up with her only bogey of the day.
"I thought that was not my mistake, I just thought to myself that it was unlucky and then I just changed my mind," added Saigo, who posted five more birdies, including three in a row at the 18th, first and second holes.
Saigo can expect a strong weekend challenge from Korda after the American posted her best round score ever at a US Open, a tournament in which her best finish was a tie for eighth in 2022.
"I feel like I've had a very complicated relationship with US Opens," Korda said. "But I'm happy to be in the position I am heading into the weekend."
Korda trending
After just one birdie and one bogey in her even-par first round, Korda finally saw some putts drop in a five-under effort that featured seven birdies.
"Honestly, I was hitting really good putts yesterday," Korda said. "I was hitting it exactly where I wanted to and they just weren't falling.
"Today I did the same thing, I didn't really try to do anything different... so hopefully I can keep trending in the right direction heading into the weekend."
Korda was tied with Japan's Hinako Shibuno, Americans Yealimi Noh and Sarah Schmelzel, South Korean Kim A-lim and Sweden's Maja Stark.
Kim and Noh were among six players who shared the first-round lead, each carding a one-under 71.
Kim, the 2020 US Open champion, shook off an early bogey to reach six-under with birdies at the seventh, eighth and 14th.
She was playing the 17th when thunderstorms halted play for almost an hour, returning to complete her par before a disappointing bogey at 18 where she was in the rough off the tee then found a greenside bunker.
Schmelzel had reached six-under with five birdies in her first seven holes, but gave a stroke back with a late bogey that left her with a 68. Former British Open champion Shibuno was six-under through 17 holes but bogeyed the last for a 69.
Noh capped her one-under round with birdies at her last two holes, the eighth and ninth, while Stark had six birdies and three bogeys in her 69.
The demanding Erin Hills layout claimed some notable victims.
World number two Jeeno Thitikul of Thailand and defending champion Yuka Saso of Japan were well outside the projected cut line of even par when darkness halted play with a dozen players on the course.