Brittany Lincicome, who is chasing her first US LPGA title since 2011, posted a one-under 71 to maintain the lead at the LPGA Championship on Saturday.
The American finished 54 holes at Monroe Golf Club at 10-under-par 206, with former world number one and defending champion Park In-Bee and Norway`s Suzann Pettersen a shot back on 207.
Lincicome, who started the day with a three-shot lead, admitted the pressure of defending that advantage hit her shortly before the round began.
"Nervous was probably an understatement," she said. "I was fine all morning. I got my 10 hours of sleep. Then when it came time to kind of eat lunch, it just wasn`t happening."
But Lincicome`s four birdies out-numbered her three bogeys. She said the nerves dwindled as the day progressed.
"Hopefully going into tomorrow it`s kind of out of my system," she said. "I kind of know what it feels like to be in this position and I will dominate again."
Lincicome, a five-time winner on the LPGA Tour is trying to become the fourth consecutive American to win a major this season, joining Lexi Thompson (Kraft Nabisco Championship), Michelle Wie (US Open) and Mo Martin (British Open).
Her resume already includes a major title at the 2009 Kraft Nabisco, but her last win came three years ago at the ShopRite Classic.
South Korea`s Park kept Lincicome in her sights with a third-round 69, while Pettersen, the 2007 LPGA Championship winner, posted a 67.
Pettersen powered home with four birdies on the back nine.
"I made the turn a bit frustrated that I three-putted nine," Pettersen said. "I actually got to the green and three-putted, which felt like I was giving away a shot. But I managed to kind of make a move ... it`s nice to make a charge and be where I`m at right now."
Park claimed the last of her four birdies at the 17th before closing her round with a par.
"I hit a couple of bad shots and kind of scrambled around today," she said. "But number 17 and 18, dropping those putts really helped me for tomorrow. Three back is quite a bit different, so I`m happy where I am right now."
South Korea`s Lee Mi-Rim (69), who won last week at the Meijer Classic, was alone in fourth at seven-under par.
New Zealand`s Lydia Ko (71), Gerina Piller (69) and Meena Lee (71) were tied for fifth on six-under 210.
Ko, seeking a first major title at the age of 17, could overtake Stacy Lewis atop the world rankings with a win this week.