BROKEN ARROW, Okla. – Cristie Kerr shot a career-best 10-under 61 on Saturday in the second round of the John Q. Hammons Hotel Classic, the top single-round score on the LPGA Tour this year.

Kerr’s course-record, bogey-free 61 at Cedar Ridge Country Club in suburban Tulsa helped her take the lead over Annika Sorenstam, who is the only LPGA player to break 60 in a round. Sorenstam shot a 59 at Moon Valley Country Club in Phoenix in the second round of the 2001 Standard Register PING.

Kerr’s previous best was a 9-under 62, which she shot last year in the first round of the Longs Drugs Challenge at The Ridge Golf Club in Auburn, Calif.

Three players have shot a 60 on the LPGA tour and five others besides Kerr have carded a 61.

Kerr started Saturday’s round at 1 under, six shots behind Sorenstam, but she shot a 6-under 30 on the front nine and needed only 13 holes to surge ahead. After hitting a slightly uphill 35-foot birdie putt on No. 13, she waved her arm as if she was carrying a lasso as she approached the hole to retrieve her ball.

Sorenstam, playing in the group ahead of Kerr, quickly tied it up with a birdie on No. 14. But Kerr also birdied the hole, hitting a low wedge to 9 feet and sinking the ensuing putt, to regain the lead and move to 10 under for the round.

“She raised the level of play,” said tour money leader Lorena Ochoa, who played in the same group as Kerr. “I wanted to keep making birdies to keep up. What she did was amazing. I’m just happy to watch that.”

Kerr said she thought about her chance to post a 59 but reminded herself not to play overly aggressive on the final holes of the 6,602-yard course. After hitting her tee shot into the rough on No. 17 she had to lay up. She got up and down to save par, then missed a 15-footer for birdie on No. 18 and is at 11-under 131 overall.

“It’s preparation meets opportunity,” Kerr said. “When those things meet, you get to the kind of place where anything you want to do, you can do. That’s what we aspire to be able to reproduce.”

Kerr will take a one-shot lead over Sorenstam into the tournament’s final round on Sunday. Sorenstam – who tied the previous course record with a 7-under 64 on Friday – shot a 3-under 68 on Saturday.

“I played very steady, a lot of fairways, a lot of greens, a lot of chances all day long,” Sorenstam said. “Pretty much down the fairway all day long. I’m very happy with that. I think Cristie obviously had a fantastic round and made my round look not so great, but I’m happy with 68.”

Kerr and Sorenstam are well ahead of the rest of the field. Allison Hanna, in third place, is at 5 under, while Ochoa, Diana D’Alessio and Jill McGill are at 4 under.

“It’s a little bit head-to-head,” Sorenstam said of her pairing Sunday with Kerr. “You can play aggressive but then you also have to deal with it. I’m going to go out and enjoy it tomorrow and hopefully make some birdies.”

The 28-year-old Kerr has eight career victories, including two this year – the Franklin American Mortgage Championship in Franklin, Tenn., and the Canadian Women’s Open in London, Ontario. In the latter, she overcame an eight-stroke deficit in the final round, shooting a bogey-free, 7-under 65 for a one-stroke victory over Angela Stanford.

Kerr has finished in the top 10 in 13 tournaments this year and is fourth on the tour money list behind Ochoa, Karrie Webb and Sorenstam.

AP-ES-09-09-06 1945EDT