Chris Evert Lloyd knows what it's like to be invincible. A record becomes an aura and then finally a force field fending all comers away. "I went through the same thing," she said. "There's only a certain amount of time you can carry on a high like that."

Now that aura belongs to Martina Navratilova, the No. 1 women's player in the world. Navratilova has beaten Evert four times this year, but she never has won the U.S. Open. Evert, the defending champion, has won it six times.

If there is justice in fate, these two women should confront each other in the final of the Open, which begins Tuesday at the National Tennis Center. "I'd like to play her," Evert said, slowly, deliberately. "I'd rather play her and take the chance than win it without playing her. I don't need to win No. 7 to prove anything."

Navratilova, the No. 1 seed and Wimbledon champion, is favored, as is John McEnroe, who has the same credentials in the men's division (Jimmy Connors, the defending champion is seeded third). Evert is the second seed, a compelling challenger, who has faced a compelling challenge this year: trying to balance the competing interests of a career that demands single-mindedness against the demands of being a wife, a normal human being.

"You have to be almost selfish," Evert said. "That's one thing I struggle with. I don't like it. I get no satisfaction from just thinking about myself. But if I want to play well, I have to do it."

How? "I have a very understanding husband," she said. "But some moments, I'm so sad I don't give more."

There have been published reports about strains in her marriage. "I was going through some growing pains," she said. "I'm 28. I probably experienced them 10 years too late."

A strange year, then, personally and professionally. "I've cruised," she said. "I was not as intense as I normally am. I never want to play if I'm not totally into it, totally intense."

She arrived at Wimbledon, buoyed by her fifth French Open title. Though she could not point to a single week all year where she had played consistently well, she was aiming for a Grand Slam or the new version of one, which does not require a player to win all four tournaments in one year.

The quest ended with a third-round loss to Kathy Jordan and a violent stomach virus. "I never get injured, but I get sick," she said. "I get run down easily. I have friends who don't sleep for three nights. I miss one night, I get up with a sore throat."

A wistful sadness filled the stadium. Evert's record of having made the semifinals of 34 consecutive Grand Slam events was over. "I had such a good record, maybe people took it for granted," she said. "Sometimes you have to lose to gain the respect and the human feelings from people. I never dwell on my own record, say, 'Boy, isn't that great?' When I saw their reaction, I let it sink in: it is a great record to have. I never let myself feel that way because I'm afraid it will be taken away."

Consigned to the players' box, she watched her husband, John Lloyd, win the mixed doubles championships with Wendy Turnbull. "I was thrilled for him," she said. "If he was No. 1 in the world, I would feel the same way about him. I think it may have given him a little more drive.

"He told me after that he had always dreamed about winning a championship there, whether it was singles or doubles. We stayed around there a while. Every day, we went to see if his name was up on the board."

This summer, she experimented with a new midsize graphite racket and lost exhibition matches to Pam Shriver and Sylvia Hanika. She lost to Navratilova in Los Angeles and jokingly suggested that Navratilova join the men's tour.

A week later in Toronto, she lost to Navratilova in three sets and, oddly, felt better. "It was just my realizing that Martina is beatable," she said. "If I had played my best and still lost, I'd have resigned myself. But I didn't play my best and I still split sets. I know I can get 10 to 15 percent better. I've gotten the sharpness back."

Evert has not beaten Navratilova since November, in the final of the Australian Open on grass. "I've let her crawl all over me, dominate the match," she said. "In Australia, I was the aggressive one. I have to change my attitude toward playing her.

"I have confidence I can beat her, I don't know how many other people can. It's up to me and the other players. There's no reason she should get worse. Even if she gets stale or drained, with her physical ability there's only three or four people who can beat her."

Navratilova has lost only one match this year, to Kathy Horvath at the French Open, and won 90 of 93 in 1982. But, Evert said, "in the past, she's gotten a little more nervous at the Open. It might be the conditions, also, not just who plays the best."

Evert says she likes to go into a big tournament with a loss. She understands why Bjorn Borg never won the Open, because it is so hard to win Wimbledon and the Open in the same year. Something for Navratilova to consider. And this too: Evert says mentally she's better than she has been all year, eager.

"My feelings about my tennis were clouded," she said. "Now it's clear to me. I've worked really hard this week. I'm in an aggressive mood. I'm ready to play the Open."