Stanley Roger Smith has climbed to the top of the tennis world with about as much fanfare as is received by the New York Jets' back-up quarterback, yet there always will be a spot for him in the hearts of Cleveland's tennis lovers. He's in town now, working out for the U.S. Davis Cup defense against West Germany.

A year ago, Smith arrived here, along with his Davis Cup teammates, to defend the Cup against an ambitious twosome from Romania, Ilie Nastase and Ion Tiriac.

PRE-MATCH interest centered on Arthur Ashe, then the nation's No. 1 player. But when the 1969 Challenge Round got underway, attention began to focus on the big likeable towhead from California.

Ashe, of course, did what was expected of him, winning two singles matches against the Romanians. It was Smith, however, who scratched and battled his way to a pair of singles and one doubles victory, accounting for three points, good enough to keep the Cup in the United States for another year.

CALLED "MR. NICE" and deservedly so, Smith, 23 a graduate of the University of Southern California, was forced to go five sets against both Nastase and Tiriac, coming from behind for both decisions. He was down two sets to love against Nastase, and behind 2-1 to Tiriac, before he rallied in singles play.

Stan's courageous plan earned for him the most outstanding player award in the 1969 Challenge Round, and by year's end he was named the No. 1 player in the United States.

THE YEAR OF 1970, however, has been one of peaks and valleys for Smith, but he believes that he's at a peak now.

Stan injured his right shoulder in March. And it took until early July for him to feel right again.

"I hurt it in Australia, wrestling with Tiriac," he said after yesterday morning's workout. "It was playful wrestling, though.

"I'm in good shape now. In fact, I'm playing better than at any time since early in the year and I'm serving hard."

WHEN REMINDED THAT he hasn't played a five-set match since Wimbledon in early July, Smith countered, "That's true, but I've played eight or nine long three-setters on clay recently.

"I'm doing a lot of running, sit ups and pushups."

Smith possesses the "big serve" and is an expert with the volley, but most of all he has unshakeable tenacity ---that's why he's no.1.