Chris Evert, who has lost only one of her last 137 matches on clay courts over a six-year period, today won the women's singles title of the French Open Tennis Championships for the third time in the most one-sided final of the post-war era.

Evert, who admits that her normally unshakable confidence slipped with seven losses earlier this year, says her rivals in women's tennis no longer have a complex about playing her. But there was little evidence of that today as she routed erring Wendy Turnbull, 6-2, 6-0, in a terribly tedious match.

Evert trailed, 1-2 in the first set, then won the last 11 games of the 63-minute romp as Turnbull made an embarrassing number of unforced errors and showed little imagination in changing a game that was getting her nowhere fast.

"She made a lot of mistakes, especially on her backhand. I was surprised because she's been over here playing on red clay for six weeks, and she's had a lot of patience in her other matches. But it was just like she wasn't willing to stay out there all day to win a match," said Evert, who won approximately $30,000, twice as much as Turnbull.

"There's a certain way to play on this court, and today she didn't play the right way . . . When I played Wendy in the finals of Forest Hills two years ago (the last U.S. Open on clay), she was a lot steadier."

Turnbull, 26, grew up on grass courts in Australia, and her natural inclination is to attack. But today she curiously went to the net only twice in the first set, and not much more often in the second. Instead, she chose to stay in the backcourt and rally with Evert, a tactic that proved to be suicidal.

"I wanted to hit my backhand short to her, and then hit another backhand down-the-line to her forehand, but unfortunately it didn't work very well at all," said the speedy Turnbull. "I tried to hit to her forehand a little more in the second set because I wasn't successful in what I started to do. But I was just hitting too many balls out. I wasn't concentrating properly."

Why didn't she attack more?

"Chrissie's got very good passing shots. It's a real challenge to her if you come to the net. You make yourself a target on this surface," said Turnbull, who has a career record of 0-10 against Evert, and has won only two sets from her, both on grass.

"I had played matches against her when I came to the net and she beat me, so this time I tried to stay back."

There was a crowd of about 10,000 spectators in the 17,000-seat stadium at Roland Garros on a hot, sunny day, the first time that the women's final was showcased as a main attraction here.

But this match did little to cultivate a long-standing interest in women's tennis on European clay.

Sixteen of the first 18 points were decided by unforced errors, and by then the pattern of loopy, yawn-inducing rallies was set.

Both players were tight and overcautious at the start, Evert particularly making uncharacteristic mistakes in the first three games. She got them out of her system quickly, however, while Turnbull did not.

Everyone kept waiting for Turnbull to take more gambles, but she never did.

One point, as she served a 2-4, 30-40 in the first game, summed up the match perfectly. Evert hit a ball inside the baseline that Turnbull had to swoop in to reach. Her momentum should have carried her to the net, but she chipped the ball deep and retreated to the baseline, where she promptly sailed a backhand long.

As long as she persisted in such foolishness, she had no chance to win.

As it turned out, the margin of victory was the most decisive in the post-war era.

Evert, 24, thus regained the world's premier clay-court title, which she held in 1974-1975. She had not played in Paris the past three years, joining most of the other top women in playing in the now-defunct Worl Team Tennis.

She is the first woman to win the singles title three times since Margaret Court, whose third victory came over Evert in 1973.That is Chrissie's only loss in 24 matches at Roland Garros.

"Because I lost more than I have in previous years, I don't think the other women are afraid of me anymore . . . Maybe they're a little bit intimidated by playing me on clay because It's still my best surface, but on other surfaces I definitely don't think so," Evert said.

"This was a good tournament for me to win because I really haven't done anything spectacular this year. This is my first big tournament, so hopefully it will give me a little bit of confidence . . ."

Evert will practice on grass next week, and then play a grass-court tournament at Eastbourne, England, in preparation for Wimbledon, which starts two weeks from Monday.

"I have to play an entirely different type of game on grass. It's a whole different mentality. But I think right now I just need the confidence of winning tournaments and winning matches," she said. "In 1974, when I won Wimbledon, I won the Italian and French first, and I think that definitely helped me."

Brother Gene and Sandy Mayer won the men's doubles title, beating Ross Case and Phil Dent, 6-4, 6-4, 6-4. Gene Mayer had won the title last year with Hank Pfister.

Turnbull and Bob Hewitt defeated Virginia Ruzici and Ion Tiriac for the mixed-doubles title, 6-3, 2-6, 6-1.

Defending champion Bjorn Borg plays unseeded Victor Pecci for the $49,000 men's singles title Sunday.