(West Lake Sammamish) Sarah Schmelzel shot a 67 to move into a deadlock at the top with Amy Yang at the LPGA Championship on Friday.
The duo posted 138, six shots under par.
Schmelzel recorded six birdies and just one bogey.
She is looking for a first victory on the LPGA, in her sixth campaign.
Yang brought home a card of 68; she avoided bogey and made four birdies.
She has a total of five wins, but none during a major tournament.
Lexi Thompson (72), Jin Youg Ko (68) and Hinako Shibuno (70) are their closest rivals, at four under.
Ontario’s Brooke Henderson is 23e to plus one, following a 72.
The Smiths Falls golfer won this tournament the last time it was held at the Sahalee club, in 2016.
Number 1 player in the world, Nelly Korda missed qualification by one stroke by bringing back a card of 81.
She struggled heavily with a double bogey and eight bogeys, including four in a row.
Korda found herself sidelined from the weekend for a third time in a row, after the U.S. Women’s Open and the Meijer Classic.
Before that, she had six victories in seven tournaments, including five consecutive victories.