In the quiet little Slovenian town of Lesce in Yugoslovia a fork- lift operator at a huge chain factory lives peacefully with his co-worker wife and two young daughters, 10 and 13. In his spare time he is a volunteer at the town's ski club, where he coaches young ski jumpers.

Back home this modest man, now in the mid-30s, is just an average guy, proud of the fact that the factory in which he works has been making chains since 1822 and shipping some of its wares to the United States.

But when he comes to America he's a celebrity. His first visit was five years ago, and he received a standing ovation at a huge formal banquet in the Waldorf-Astoria ballroom.

He's back this week, sightseeing and shopping in New York. On Saturday night he will be on national television. Millions will enjoy seeing this fellow.

His name is Vinko Bogataj.

Oh. Who's Vinko Bogataj? He's the ski jumper who veers off the side of the chute, crashing and tumbling down the snowbank in the opening sequence of ABC's "Wide World of Sports." His ski-pole-over-ski-cap spill and the phrase "the agony of defeat" are one in the hearts and minds of viewers who have seen him somersault in the snow for more than 15 years. He will be part of Saturday's two-hour special commemorating the show's 25th anniversary.

ABC coordinating producer Dennis Lewin saw Bogataj's pratfall on TV in 1970 in Ljubljana. Bogataj was taken unconscious to a nearby hospital, where it was learned that he was not seriously injured. He suffered a mild concussion. "I would never have used the footage in this manner if he had been a serious injury," said Lewin.

What was the first thing Bogataj did when he awoke at the hospital? He placed a call to make sure he was entered in the same event the next year.