Going into this summer's Wimbledon final against Chris Evert, Martina Navratilova was a queen without a scepter, a champion without portfolio. She had won eight of 11 tournaments and 56 of 59 matches in 1978, but the throne was not yet hers. Not in the public's mind, not in her own.

Her unprecedented winning streak on the Virginia Slims circuit at the beginning of the year - seven consecutive tournaments, 37 matches - was achieved while the reigning monarch, Evert, was away from the palace.

The "new Martina" - fit, dedicated, composed and not given to the tearful outbursts and on-court swoons of the past - could not be validly assessed until Evert returned from her four-month vacation and confronted her on an occasion of consequence.

They did play in Eastbourne, England, the week before Wimbledon - Navratilova came back from 1-4 in the final set and saved a match point in winning a breathtaking contest - but that was only a tuneup. Psychologically important, no doubt, but clearly a nontitle bout.

Both players know that only Wimbledon would decide.

"I was No. 1 for the year, but not number one No. 1, you know, because I hadn't beaten Chris in a big tournament. I knew that is what it would take," Navratilova said yesterday, after surging past Ann Kiyomura, 6-4, 6-2, into the quarterfinals of the U.S. Open. "All the tournaments I won she wasn't there, so I felt I had to beat her to prove myself."

Navratilova was seeded No. 2 at Wimbledon. Evert - winner of two Wimbledon, three U.S. Open, two French and four Virginia Slims championships, and the top-ranked woman in tennis for four years - was No. 1. Still, Navratilova felt neither like challengee. She was a bit of both.

"It was like 50-50. I had won everything while she was away and beat her at Eastbourne, so she had to prove herself as well. I felt it was kind of like two different worlds meeting, like Seattle Slew running against Affirmed or something like that," Navratilova said. "Who's challenging whom? You don't know because they're both winners."

That is what makes the Marlboro Cup, the upcoming first meeting between the two aforementioned Triple Crown-winning thoroughbreds, so fascinating. And that is why the women's singles final at Wimbledon was especially significant.

Only after she had beaten Evert in the showdown, coming back from a 2-4 deficit in the final set with impenetrable serving and unflappable cool to win, 2-6, 6-4, 7-5, could Navratilova look in the mirror and see number one No. 1.

The importance of that victory to her is revealed in the fact that she has watched it several times on tape, most recently Saturday night at the apartment of Milos Forman, the noted Czech director ("One Flew Over the Cuckoo's Nest") who lives in New York and is currently working on the film version of "Hair."

"There were eight of us - my cousin, some friends from Chicago, all Czechs," said Navratilova, 21, who defected from Czechoslovakia three years ago this week. She lives in Dallas, thoroughly Americanized, but remains a Czech at heart.

"We had some wine. They were playing all Czech songs. Then Milos dragged all eight of us into his bedroom and we watched the last set on his videotape machine," she recalled.

"When I was up two-zip in the first set, I just fast-forwarded the tape. We skipped the four games I lost. I didn't want to watch those. We watched the last four, hen I came back to win."

Navratilova knew that if she had watched those four games she lost, she would have seen herself playing tentatively, safely, trying to guard instead of enlarge her lead. She knew that was her mistake because, as she said, "I remember every point from that final." She has played the tape back in her mind a million times, and analyzed it.

"Now I know what I should have done differently, especially the psychological aspect," she said. "I just tried to get the ball back. I was trying to preserve the victory instead of going after it. I know that if I get into that position again, I can't do that. I've got to keep going for my shots, attacking, playing the same way."

She said there is more pressure on her this week because she is the champion, Chrissie the challenger. Even though Evert is seeking her fourth straight U.S. title, a feat no woman has accomplished since Helen Jacobs in 1932-35, she is seeded No. 2. Navratilova is No. 1.

"I'm more nervous now because I have to keep performing, to prove myself again. People expect more since I won Wimbledon," said Navratilova, who took a cortisone injection to relieve the pain of tendenitis in her left shoulder three weeks ago.

Like many players here, Navratilova has found it difficult to convince herself that this is the U.S. Open. She has not gotten accustomed to the National Tennis Center in Flushing Meadow Park, new home of a tournament played for 54 consecutive years at the West Side Tennis Club in nearby Forest Hills.

"It just doesn't feel the same. I haven't felt any atmosphere yet. I have to keep telling myself that this is the second most important tournament in the world," she said after her second appearance on the rubberized asphalt hard court in 19,5000-seat Louis Armstrong Stadium, centerpiece of the $10 million tennis complex on the site of the 1964 World's Fair.

"Everything is so different, and after Wimbledon everything is a letdown, so it takes a while to get psyched up. Nobody referred to Forest Hills as the U.S. Open. It was 'Forest Hills.' This is the U.S. Open because it wouldn't mean anything to say you're playing 'Flushing Meadows.'

"But I still say I'm playing Forest Hills. It's easier to get psyched up that way. I still come here the same way I used to go to Forest Hills, but I don't get off the subway there."

Watching herself in Wimbledon on Milos Forman's videotape machine helped get her juices flowing, too.

"I get excited all over again when I think about it," she said. "Since this doesn't feel like the U.S. Open, I get psyched up watching Wimbledon."

After all, winning Wimbledon altered her life and self-esteem - though not quite in the ways she expected.

"I get recognized a lot more on the street. I've been surprised at how much impact I had. People know my name and my fact a lot more."

Does she like her notoriety and visibility?

"It depends on how people approach you. When they start screaming out in the middle of Fifth Avenue, 'Hey, there's Martina!' you feel like hiding somewhere. But generally I enjoy it. I don't think there's anyone who can say they don't enjoy being recognized. It's good for your ego," she said, smiling.

Now she is a champion with portfolio, a queen with a scepter.

Men's Single - Fourth Round

Vitas Gerulaitis def. Bob Lutz, 4-6, 6-4, 6-3, 6-4; John Frick def. Brian Teacher, 7-6, 6-3, 7-6; John McEnroe def. Collin Dowdeswall, 7-6, 6-3, 6-3.

Women's Singles - Third Round

Betty Stove def. Anne Hobbs, 7-6, 6-2; Kathy May def. Hana Kloss, 6-2, 6-7, 6-1: Wendy Turnbull def. Sandra Collins, 7-6, 1-6, 6-4; Anne Smith def. Beltina Banga, 6-3, 6-1; Regina Marsikova def. Zenda Lisse, 6-4, 6-1; Martina Navratilova def. Ann Kiyomura, 6-4, 6-2.

Fourth Round

Virginia Ruzicki def. Stacy Margalia, 4-6, 7-6, 6-4.