The Open kicked off on Thursday with the field playing in threesomes starting from either the first tee or the tenth tee. Featured threesomes included Annika Sörenstam, Suzann Pettersen, and Paula Creamer, ranked 2, 3, and 4 respectively in the world rankings. Sorenstam and Petterssen opened their U.S. Opens with scores of 75 (+2) and 77 (+4) respectively. Creamer shot a 70 to move three shots off the pace. The other featured threesome included number one ranked player Lorena Ochoa, defending U.S. Open champion Cristie Kerr, and 2007 U.S. Women's Amateur champion Maria José Uribe. Uribe led that group with a 69 to lead all amateurs and end the day in a tie for fourth overall; Kerr shot a 1-under 72; Ochoa had an up-and-down round of even-par 73. The rounds of the day belonged to Ji Young Oh, who had eight birdies and two bogeys and to Pat Hurst who had six birdies and an eagle. Oh and Hurst tied after Round 1 at six-under par 67.
With Thursday's rounds completed many well-known American players took a step down on the competition while many lesser-known and international players took a step up. A two-hour weather delay required some to finish their rounds on Saturday morning. Angela Park had an even round on Thursday, and a 6-under 67 in the second round. She held a one-stroke lead over three others: Inbee Park of Korea, Helen Alfredsson of Sweden, and the only Finnish player in the tournament, Minea Blomqvist. The two leading Americans were Paula Creamer and Cristie Kerr at 4-under 142. Both first-round leaders took a severe fall on Friday, with Ji Young Oh, who had to finish her second round on Saturday due to the weather delay, shooting a 76 and Pat Hurst turning in a 5-over 78. Many top-ranked or well-known players missed the cut, including Laura Davies (70-81), Natalie Gulbis (73-80), 13-year-old Alexis Thompson (75-77), 2003 champion and Minnesotan Hilary Lunke (74-78), Juli Inkster (74-81), and Michelle Wie (81-75).
