Six thousand eyes saw the tennis ball fly beyond the white line, but two decided it was an honest shot, well struck, perfectly placed. So the linesman just sat there. The ball moved back and forth again, finally eluding Dianne Fromholtz, who then, as she would later say so prettily, "went bananas." Hers were among the eyes that judged the linesman blinder than a cold stone.

Fromholtz threw down her racket. She jumped up and down. She made this perfectly horrible face, as if the linesman had threatened to cut off her blonde pigtails, and she said something. "Beekrggharw," she said. Three thousands voices joined in the refrain sung in the linesman's honor.

The chair umpire, Flo Blanchard, an old hand at tennis justice, earlier had asked a linesman to reconsider a call. He said no. This time she cut out the pleasantries, so atrocious was the linesman's vision, and said, "Will you yield to the chair?"

He did. Fromholtz was given the point. It meant little in the match, a Virginia Slims semifinal eventually won in three sets by Martina Navratilova, who figured to win much more easily. So easily, for that matter, that one little point would not be worth a banana fit. But Dianne Fromholtz thinks she is onto something at last.

At 21 a world class player for five years, the Australian lefthander never has won anything worth mentioning. Her record is full of notes saying she reached the semifinals of this tournament, the quarters of that. Occasionally an "RU" appears, which means she was just good enough to lose when a championship was there for the taking.

She earned almost $100,000 playing tennis last season, $14,575 of it on the Slims tour. She was ranked 10th in the world. Clearly, she ain't chopped liver, but when you have this idea you want to be the best in the world - and when the best, Christ Evert, won $503,134 - then the poverty-stricken hundred-grander has a ways to go.

It was heartening for Fromholtz to go three sets with Navratilova yesterday at George Washington University's Smith Center. She has beaten the Czech genius only twice in eight tries. What made it nicer yet for Fromholtz was the way she did it. Once nailed to the baseline, never leaving it except in case of earthquakes, Fromholtz now turns up at the most amazing places. Like, say, at the net.

"She's a different player," Navratilova said, her voice full of surprise. "Now she comes to the net on top of everything."

In her two earlier victories over Navratilova, Fromholtz said it was not so much talent as sheer bullheadedness that decided the issue. "I was just gusty then," she said. "I just outlasted her. I stood on the baseline and kept hitting it back. But I finally had to quit that."

Exhaustion is why. "I'd get too tired. You can't stay back all the time unless you can put your shots on a dime. Sometimes I could. Sometimes I couldn't."

So six weeks ago, Fromholtz decided to leave the baseline to Chris Evert and Harold Solomon. "This is more fun," she said, smiling in defeat yesterday. "Now I come up to the net and kill the ball. I used to hate the baseline."

She had no choice, though. Her serve, she said, was weak as American beer. "I'd serve one ace a year," Fromholtz said. "I'd get my first serve in once a month." She may have had a terrible serve, but she couldn't volley at all. Take the cape and sword away from a bullfighter and what does he do? He runs a lot. Without a serve and volley, Fromholtz ran all day.

You'd never have known it yesterday. Against the woman who won $300,000 last year and is probably Evert's athletic superior, Fromholtz was a tigress looking for ways to bring down her greatest prey. She attacked Navratilova's big first serve, sending forehand returns back too hot to handle. She bounced the Czech from side to side, then put away volleys time and again.

Even down 4-1 in games in the last set, Fromholtz stalked Navratilova. She held serve without losing a point and then, at deuce on Navratilova's serve, she forced the 300-grander into a weak, reaching forehand. Fromholtz put away a backhand volley that, she would say later, probably was beyond her ability six months ago. A backhand crosscourt, twisting the racket in Navratilova's grip, won the game.

It came even, this wonderful match did, when Fromholtz lost only a point on her next serve, but a certain inevitability surface when navratilova held her serve, winning the last three points without Fromholtz getting a shot back.

"With the way I had been playing, I'd produce some good matches, but the way I play now, it produces a lot of good matches," Fromholtz said. Then she smiled, her blue glorious, and said this new style would help her from now on."If it doesn't, I'll put my head in a bag," she said.

She's felt that way before. Because she grew up two blocks from margaret Court's house in Sydney. It seemed foreordained the great Aussie tennis queen would pass on her wisdom to this tiny blonde who wanted to be the best in the world. The tried.

The 19th-Century dancer, Isadora Duncan, once suggested marriage to George Bernard Shaw, saying a child of such a union would be perfect, inheriting her body and the playwright's brain. "But what, my dear," Shaw replied, "if the child should have my body and your brain?" What Margaret Court proposed to give to Dianne Fromholtz was Margaret Court's tennis game, an ill fit both psychological and physically.

"She tried to change the way I hit everything," Fromholtz said. "When I was young, I could volley. But when Margaret got through with me at 17, I couldn't hit anything. Balls were going all over the place."

Fromholtz tried to be Margaret Court II for two years. "I am very determined," she said. Now, two years later, she's finding out it's more fun to be Dianne Fromholtz I.