Leonard Roscoe Tanner Jr. of Lookout Mountain, Tenn., a distinguished, white-haired gentlemen of 63, was sitting with his wife Anne under the vast green canopy of the Wimbledon Long Bar. Thursday afternoon an hour after their son -- Leonard Roscoe Tanner III -- had beaten fellow Stanford Grad Pat DuPre to reach the final of the Wimbledon tenniss championships for the first time.

An affable but reserved man, senior partner in the Chattanooga law firm of Tanner and Jahn, the elder Tanner was dressed in his usual conservative manner -- dark blue suit, white shirt, striped tie, black wing tips. He spoke in sloww, measured, precise sentences, as if dictating a law brief. But his foremal speech pattern could not conceal the intensity of his fatherly pride.

"It's difficult to express what this means to Mrs. Tanner and me, because tt's the culmination of effort and desire that extends over a period approaching 20 years," he said.

"In the early years, I never had any idea that Roscoe would excel at a world level. I simply wanted him to be a good enough player to be known in the community and the South, because I though it would be a good thing for him as lawyer to be known for something other than law.

"I wanted him to practice law with me and I though he would until he started to make his move internationally during his thrid year at Stanford.

"That's when he really started to show promises against players of world classs, and at that time I was both pleased and unhappy: pleased for him and unhappy because I thought it would jeopardize the relationship I hope to achieve as father-and-son lawyers.

"I still have mixed emotions. I had always thought he would go to law school after Stanford [B.A in political science, class of '75]. But I think it is probably best for him that it worked out the way it did.

"Professional tennis gives him opportunities that few people second to . . . .contacts with prominent people all over the world, opportunities to travel and develop business interests and relationships internationally, and to lead what I would regard as a well-rounded life, with financial security. I was 55 years old when I arrived at that point. He is 27, and there already."

His formative tennis years were spent at Baylor School a private military school for boys in Chattanooga where Jerry Evert, Chris Evert's uncle, was Roscoe's math teacher and tennis coach.

"It was Jerry who taught Roscoe his great serve. He still has the same basic strokes Jerry gave him, but of course his present coach, Dennis Ralston has done a remarkable job of making him a better tournament player."

"Roscoe's "breakthrough year" was 1966.

"That was the year Ramsey Earnhart [a former touring player] married my oldest daughtter, Sherry Anne, and moved to Chattanooga as a teaching p. He helped Roscoe enormously And Roscoe grew seven inches that one year. Every time you turned aroun, the cuffs of his pants were too high. . . The improvement in his game was unbelievable, and he started beating players he had never beaten before -- includng me and all my friend.

"We always got a chuckle when Rosecoe first began to make a name for himself and everybody thought he must be a barefoot hillbilly, and his dad a moonshiner," said the elder Tanner, scion of a respected Tenessee family whose lineage may go back to the British royal family. (Tanner's possble kinship with the queen has become a small cause celebre here, and generalogists are checking out the blodliness this week.)

"Lookout Mountain is actually a very affluent, sophisticated community. We overlook the east valley and can see for 75 miles. On a clear day, they say we can see seven states: North Carolina South Carolina, Alabama, Virginia, Georgia, Kentucky and Tennessee. We're 2,500 feet above Chattanooga, and the view is just like what you'd get from an airplane."

That is how high Tanner's father felt when his son beat DuPre, 6-3, 7-6, 6-3, to reach Saturday's final against defending champion Bjorn Borg. His pride in his son's accomplishments is immense.

Predictably, they don't think their son should be the "out-bet" against Borg that many peoplem, including most of London's bookmakers, are making him.

1papa Tanner had looked on, bemusedly, as Roscoe praised Borg to the sky in a press conference after the semifinals. Roscoe spoke glowingly of the Swede's improved serve and incomparable ground strokes, and he mentioned that "Guys have tried all different kinds of games against him, and nothing has worked.

"I don't know if I'll have something that will work. I haven't really thought too much about it yet, because tt's not a very pleasant task to think about playing Bjron."

"That interview was light-hearted but the desire in this boy to win Wimbledon is deep-seated," the father said. "I mean, it goes right down to his toes. Ever since he got serious about tennis, he's had three goals: to win Wimbledon, the U.S. Open and the Davis Cup for the United States. But Wimbledon was always No. 1, I know how much it means to him."

And to his parents.