R1 LEADERBOARD -8 Annika Sorenstam (Swe) -7 Gloria Park (Kor), Cristie Kerr -6 Lorie Kane (Can), Paula Creamer -5 Natalie Gulbis, Grace Park (Kor) Others: -3 Michelle Wie (US unless stated)

Hawaii's Wie, 16, who turned pro last week, was six shots behind Sorenstam after Sweden's world number one fired a stunning 64 at Bighorn, California.

Sorenstam led by one from Korea's Gloria Park and Wie's playing partner Cristie Kerr of America.

Canadian Lorie Kane and 19-year-old Paula Creamer were locked on six under.

Wie, who has already signed sponsorship deals worth $10m, recieved an invite to the elite 20-strong field on the strength of her impressive amateur performances.

Her opening drive at the 405-yard first hole at the Canyons Course was recorded for posterity by rows of cameramen and she went on to make a routine par.

My heart was thumping when I stood over the first shot, but I soon calmed down Michelle Wie

Wie birdied the second and picked up another shot at the seventh to turn in 34.

She made further birdies at the 10th and 12th to reach four under but marred the card with dropped shots at 14 and 18.

"I think I did pretty well, although it could have been better," said Wie, who played in 24 LPGA tournaments as an amateur and has four top-10 finishes in majors.

"My heart was thumping when I stood over the first shot, but I soon calmed down.

"I didn't really feel any different than playing as an amateur. It was just a lot of fun.

"I wasn't thinking about the money, but it will be nice to get a cheque on Sunday."

Sorenstam, 35, who is chasing a fifth win in this event, carded five birdies on the front nine and three more coming in as she played almost perfect golf from tee to green.

But the nine-time major winner missed makeable putts on the final two greens.

Asked if she felt she had a point to prove in the face of Wie, Sorenstam said: "No, I don't think I have anything to prove.

"I know where I am on the money list and what I have achieved.

"But I wish Michelle well. It's exciting that she's now turned professional and I think she will be able to handle it."