WILLIAMSBURG -- If you can imagine an encounter between a hungry wolf and plump lamb, you can imagine the outcome of the first round of the Michelob Ultra Open.

The world's best female golfers attacked Kingsmill's River Course yesterday with fangs unsheathed and claws extended. The course could do little more than bleat in response. Mhairi McKay, a 33-year-old LPGA veteran from Scotland, matched the course record with an 8-under-par 63. Eleven other players posted rounds of 5-under or better on a cool, damp day that promised -- and delivered -- fearless shotmaking.

"It's a really fun course to play and the greens are superb, and right now there are opportunities to make some birdies out there," said McKay, who leads Annika Sorenstam and Sun Young Yoo by one stroke and Lorena Ochoa, and Diana D'Alessio by two.

Ochoa agreed. She said rain that fell steadily yesterday morning and intermittently around noon rendered the greens all but defenseless. Dropping an approach shot onto the putting surface was approximately as challenging as dropping a raisin into a bowl of oatmeal.

"We could be more aggressive because the ball didn't have that 7-, 8-, 10-yard release" upon striking the putting surface, Ochoa said. "It was more like two or maybe three yards." When conditions are so benign, she said, "you've got to take advantage."

McKay did. She rang up eight birdies and no bogeys, in the process securing a unique distinction: "I shot below my age on both nines (32-31), so obviously I feel really good. Maybe that should be my goal all year long."

A lethal putter enabled McKay to transform a good round into a keepsake. She sank three putts of 20 feet or longer. She said her brother, Kenneth, who caddied for her in last week's Scottish Open, deserves at least partial credit.

"He thought my body was coming out of the putting stroke a bit too soon. He gave me something to focus on: staying over the ball a little bit longer and maybe a little bit lower. It's kind of made a difference. For sure, it made a difference [yesterday]."

Sorenstam's round was three strokes better than her previous best at Kingsmill. She piled up seven birdies and no bogeys while offering prolonged glimpses of the skill and savvy that enabled her to win five LPGA player of the year trophies between 2001 and 2005. Was she endeavoring to send a message to playing partner Ochoa, who has replaced her atop the world rankings? Sorenstam shook her head.

"Making a statement on Thursday really doesn't matter," she said. "There are three more days. Anything can happen. It's never about making a statement" on the first day. "It's about playing good golf, one shot at a time, and trying to put yourself in position to win a championship on Sunday."

Yoo, a former South Korean junior champion, finished with a flourish. She made birdie on each of her final four holes.

Eagles lifted D'Alessio, a New Jersey native; and Ochoa toward the top of the leader board. D'Alessio, winless in eight-plus seasons on tour, sank a 134-yard 7-iron on the par-4 16th. Ochoa, who already has won five times in 2008, eagled the par-5 seventh hole after knocking her second shot, a 5-wood from 218 yards, to within five feet of the flag.

Ochoa said she all but ignored the rain that fell on an on-and-off basis throughout her round.

"I try to be happy with what we have," she said. "It's the same for everybody. If we have rain, well, that's just the way it is. I don't waste too much energy on things out of my control."

Six players are clustered at 5 under. Among them: Stacy Prammanasudh of Oklahoma, the only other American-born player in the top 10.