When Joan Benoit strolled through the Los Angeles airport several weeks ago, she went unrecognized by milling travelers. Given her small and fragile appearance, there was no reason to suspect that she was a potential Olympic heroine - or one of the toughest competitors around.
But by winning the first women's marathon in Olympic history with a spectacular effort on Sunday, Benoit answered to both descriptions.
Already a big name in running circles, the current world record holder from Freeport, Maine, has now become a familiar face to the general public. After all , a huge viewing audience got a good, long look at her as she ran into the teeth of ABC's international TV coverage.
Not only did she win with the third-fastest women's marathon time in history (2:24.52), she did so without letting a talented international field get anywhere close, after she pulled away early in the race. Her journey was one of the most gripping solo flights since Amelia Earhart crossed the Atlantic - and one of the most thunderously received.
It began at 8 a.m. local time in Santa Monica, wound its way near the coast, and then headed inland to the L.A. Coliseum.
There, in what is traditionally a dramatic moment in any Olympic marathon, she ran through the tunnel and onto the track. Some 70,000 spectators rose in roaring salute, to which the 5 ft. 3 in., 105 lb. New Englander responded by doffing her hat.
Commenting later on her strategy, she said that she decided about two months ago to use ''the tactic of going out fast.'' ''I knew I had to run my own race, '' she explained, ''and not worry about the rest of the field. I still can't believe it all worked so well.''
The only runner who even saw her at the end was Norway's Grete Waitz, who entered the coliseum as Benoit was completing her finishing loop of the stadium. Waitz, a five-time winner of the New York Marathon who competed in two prior Olympics at 1,500 meters, was about a minute and a half behind. Rosa Mota of Portugal, a runner more accustomed to California-like heat than some of her rivals, came in another 39 seconds later.
Was Benoit exhausted by her tremendous effort, as one might reasonably have expected her to be? She showed she wasn't by grabbing a large American flag and waving it exuberantly. A bit later she scurried about looking for her parents, who made their way down through the cheering crowd to embrace the new queen of the Marina Freeway. The scene conjured up memories of hockey goalie Jim Craig searching out his dad amid the pandemonium at Lake Placid, N.Y., four years earlier.
Nancy Benoit, as it turns out, once cautioned ''Joanie'' about running marathons. ''If marathons make you look like this,'' Mrs. Benoit wrote on a note attached to a finish-line picture of her daughter, ''please don't run any more.''
Instead of discouraging Joan, however, the message only made her more determined. Behind the soft, apple-cheeked exterior lies an athlete who won't quit - with an efficiency of style matched by a strength of character that's as solid as her beloved Maine coast.
One could find no better proof of the latter fact than her performance in the Olympic trials. Only 17 days after knee surgery, she showed up at Olympia, Wash. , needing to finish in the first three to qualify. Some questioned whether she'd be able to run the 26-mile, 385-yard distance under the circumstances. But Benoit just got down to business and won by a wide margin.
That gritty performance added even more luster to a career that in just a few years had pushed her to the forefront of all-time female distance runners. Joan first burst into prominence in 1979 when, as a shy senior at Bowdoin College, she won her first Boston Marathon with a new American record. Four years later, while serving as the women's distance coach at Boston University, she lopped 2 minutes and 47 seconds off the world mark in winning the famous Boston race again.
Her time of 2:22:42 was an excellent one by any standards, male or female, and in fact would have been good enough to win every men's Olympic marathon through 1956. Undoubtedly that effort, along with the significant improvement of women's times in general, went a long way toward overcoming the longstanding resistance of Olympic officials to including women's distance races in the games.
In setting the world record, Benoit had a male marathoner-turned-TV-reporter running alongside her - which led some observers to question whether she would be able to do quite as well without someone setting a pace for her. Here in Los Angeles, however, there could be no doubt about the effectiveness of Joan's own built-in metronome. She ran alone virtually all the way, leaving the rest of the field to battle for second place.
Silver and bronze medalists Waitz and Mota also secured niches on this historic occasion, of course, but it was Switzerland's Gabriela Andersen-Schiess who engraved the moment with unforgettable pathos. Utterly depleted, she staggered into the stadium. Though unable to stand upright, she refused assistance, and spent some five agonizing minutes weaving her way to the finish line.
Some observers questioned the wisdom of letting her continue - a decision sure to stir debate. She was certainly not a pretty sight, yet her courage will remain one of the enduring symbols of these or any other Olympics.
In a less enlightened time, her struggles might have been interpreted by some as a sign of female weakness - just the sort of thing that led Olympic officials to discourage women's distance events until recently. Such thinking, many observers note, has pretty much disappeared by now: With the promise of more exhilirating races such as Benoit's, the International Olympic Committee will probably not only keep the new races that were put on the program this year but also add a women's 10,000-meter event in 1988.
Both the marathon and the 3,000 meters, which Mary Decker and Zola Budd will run here Friday in their long-awaited showdown, are new this year. Decker is pushing as well for a 5,000, which the men already have. After the Olympics, Decker, the world 1,500- and 3,000-meter champion, says she will give more time to the 5,000 and 10,000.
''They need to be run more,'' she said recently. ''I think the times in those events will come down dramatically in the next few years, and I'd like to be a part of that.''
So might many other women, who increasingly will aspire to follow in the tracks of both Decker and Benoit.