The morning sun was making its first stab through the clouds above Brooklawn Country Club and Jane Blalock, one over par after two holes of the United States Women's Open, tugged her visor down an inch to shade her eyes. From under the shadows which formed around her face, one could see Blalock's mouth moving.

"Just getting ready," Blalock said later on this day that ended with Jerilyn Britz and Debbie Massey leading the field with 70s.

It was, Blalock admitted, nothing out of the ordinary. Donna Caponi Young has watched Blalock do stranger things, like walk off to a clump of trees minutes before the beginning of a round.

"She'd start off quietly," Young said, "And by the time she's done, she's yelling." Sometimes, Blalock isn't even aware of what she is doing."Sometimes," Blalock said, "I can be with a lot of people and still be by myself."

Today, for instance, moments after the Open had begun for Blalock and Laura Baugh and Hollis Stacy, the two-time defending champion, Stacy and Baugh were in the middle of the third fairway, which was lined with hundreds of people. All of which hardly mattered to Blalock, facing the possibility of another bogey, her ball in the rough. "I needed something," blalock said.

What she got was nother private pysch job. And a birdie on No. 6. And another on No. 9 That she finished with even-par 71, as did Stacy and four others, pleased Blalock. That she stood one in back of the leaders encouraged her.

"But it's not what they do, it's what I do," Blalock said. "The Open is different than other tournaments. It's a personal challenge."

Jane Blalock is used to challenges.

In 1972, her peers on the Ladies Professional Golf Association tour accused Blalock of cheating, of moving her ball marker on the greens, and suspended her. She went to court. It took three years to clear up, but Blalock won.

In 1976, when the late Clifford Roberts of Augusta, Ga., brought suit against a sponsor for trying to start a Ladies' Masters, LPGA Commissioner Ray Volpe called on Blalock to testify on behalf of the women players. The suit was lost but Blalock won back may friends.

"What happened to Jane would probably make or break anybody," said Carol Mann, who helped resolve the cheating controversy. "You either pass or fail as a person first and then as a golfer. Jane passed and I think it has carried into her game."

That much is evidenced by her record. It is unmatched on the tour in its consistency; Blalock has not been out of the top 10 since the incident took place. This year, she is behind only Nancy Lopez and Sandra Palmer in earnings and could pass them both with a victory here at the Open. The money now, Blalock says, is secondary. Blalock wants very badly to win the Open.

"The desire to succeed is greater this time than it has ever been," Blalock said. "I grew up on courses like this. I don't get intimidated by them,"

Nor do competitors like Lopez and Stacy and Palmer.

Blalock will be 34 in September and feels she is now reaching the top of her game. She has won four times already this year and a come back from a nerve injury which paralyzed her left arm for a week a couple of months back. That there are smiles in the locker room, instead of cold stares, had helped.

"I've been through a lot more than most people on the tour," she said. "I appreciate being able to play more than a lot of other players. I appreciate my friends. I appreciate being happy. Believe it or not, I'm having the time of my life."

Lopez and Baugh came in three shots off the lead . . . Pat Bradley, the tour's fourth-leading money winner, shot 77 . . . Lori Rinker, at 16 the youngest player in the field, carded 75. CAPTION: Picture, Jerilyn Britz