''Everything was falling and I was just on a roll,'' Korda said. ''You don't take these days for granted.'' Putting with her left-hand low, Korda had 11 birdies and one bogey to get to 20-under 196 at Blythefield Country Club. She broke the tournament's 54-hole record of 17 under set by Lexi Thompson in her 2015 victory.

''A bit of everything,'' Korda said. ''Mental, putting, especially left low again. I went back, and then I just feel like my putting is better left-hand low.'' The 22-year-old American, ranked No. 4 in the world, birdied the last three holes and five of the last six in the round interrupted by a rain delay.

''Definitely got a lot softer,'' Korda said. ''You can be a lot more aggressive on the greens. As I said yesterday the greens get bouncy, they're a little slower but bouncy. For them to be soft, I can just aim at the hole and shoot at it.'' Korda birdied the first three holes, added three more on Nos. 6, 8 and 10 before dropping a stroke on No. 11. She birdied Nos. 13 and 14 and closed with three straight to push the lead to three.

She won the Gainbridge LPGA in Florida in Orlando, Florida, in February — after her older sister, Jessica won the previous tour event — for her fourth LPGA Tour victory.

''Every time is different I guess in a sense,'' Korda said. ''I've gone to sleep and I haven't been nervous, and there have been times where I couldn't even sleep I woke up so many times during the night. We'll see tomorrow if I'm rested or not.'' Younger brother Sebastian won tennis' Emilia-Romagna Open in Italy in May for his first ATP Tour victory.

Second-round leader Maguire was second after a 70. The 26-year-old former Duke player is trying to become the first Irish winner in LPGA Tour history.

''All the pressure is on Nelly. Everybody expects Nelly to win tomorrow,'' Maguire said. ''She's ranked whatever she is in the world, top five. Nobody expects me to do anything tomorrow. I've really got nothing to lose. I can just go out and play golf and see what happens.'' Madelene Sagstrom was third at 16 under after a 65, and Su Oh (69) was another stroke back. Anna Nordqvist (68), Georgia Hall (65), Charley Hull (67) and Mina Harigae (68) were 14 under.

Jessica Korda was eight strokes behind after a 67. Thompson (68) and Inbee Park (68) also were 12 under.

The major KPMG Women's PGA Championship is next week at Atlanta Athletic Club.