The American deflated three eagles en route to carding an 11-under 61, a new course record for La Reserva Club.
Three birdies on either side of the corner helped consolidate a historic day for the 29-year-old, who has a five-stroke lead into the second round of the individual event.
“It was a great lap,” Korda told reporters. “We had a great atmosphere in the group and so I was obviously very relaxed.
“I’ve never done three eagles in a round before, so I’m definitely going to remember this one!”
A bogey on the eighth hole marked the lone blemish on the world’s number 14 scorecard, tarnishing her chances of hitting the Tour’s first-ever sub-60 score.
“I was still bogeying and hitting it in the danger zone, so I wouldn’t say every aspect worked,” Korda said.
“Over the past month and change, I think I haven’t really converted putts and the floodgates opened today and hopefully they can continue tomorrow and that’s the beauty of golf.”
Belgian Manon De Roey and Slovenian Pia Babnik led the chasing pack after carding six-under 66s.
Korda’s sister Nelly is still one stroke behind after shooting 67, with a double bogey on the par-five sixth hole wiping out an eagle on the second. The number 3 in the world shares fourth place with the French Pauline Roussin.
“I played pretty well,” Korda said. “It’s my first time in Spain and it blew me away, it’s super fun.”
The 54-hole individual event will run alongside a 36-team event, where a team of four – including an amateur – will compete against each other, with the best two counting per hole. Each event offers a prize pool of $500,000.
Now, 10 months later in Sotogrande, she is well placed to repeat the feat after her team – made up of Finland’s Noora Komulainen, Czech Tereza Melecka and amateur Malcolm Borwick – finished 19-under and led by a stroke halfway through the stage.
“We had a good atmosphere in the team, we really kept it loose there,” Korda said.
“I know the girls were a little nervous at first, but I told them there was nothing to be nervous about and go out and have fun and play some golf.
“We are in Spain and the weather is beautiful, we are lucky to be here.”
The teams of Roussin and De Roey follow a shot for Friday’s decision-making round.