'I feel great,' Sorenstam said off the 18th green.
'I shot under par in the Open, it's obviously better than other tournaments,' she went on to say, obviously forgetting that she finished even-par 70.
'It was a difficult day. But I hung in there. It's kind of hard to wake up and get loose. But it's nice to get off first.'
The owner of back-to-back U.S. Women's Open titles (1995-96) recorded a double bogey on the 401-yard par 4 14th as well as two other bogeys during the first round. Four birdies, two of which fell on the front nine and the other two on the back, saved her position at par at the end of the day.
Sorenstam isn't far behind, however. The leaders, Cindy Figg-Currier and A.J. Eathorne, each shot 3-under-par 67.
Full-field scores from the U.S. Women's Open