Fifteen years after he was the top-ranked U.S. player, Cliff Richey seems to have changed little.

He still stands on the baseline, knocking the clay from his shoes with his racket like a baseball player tapping his bat against his cleats. He still dives for the ball the way Pete Rose dives into third base. And, yes, he still argues with linesmen. At 38, Richey is no genteel country-club volleyer. But that is fitting; he never was.

Richey advanced to the final of the $40,000 Prudential-Bache Securities Grand Champions Tournament yesterday by defeating Jaime Fillol, 7-5, 6-4, at Rock Creek Tennis Stadium. He said he is enjoying the game more as a member of the 35-and-over tour than he did the last four or five years he played the regular Grand Prix circuit.

"It never really looks like I'm enjoying it when I'm out there, agonizing and grinding away, but as far as I'm concerned this tour is more enjoyable," he said.

Richey will face Andrew Pattison, a 6-4, 6-4 winner over Marty Riessen in the other semifinal, for the championship at 1 p.m. today. Long-time Washington tennis fans still might remember Richey best for the time he disputed a linesman's call by reaching down and pulling the line tape up from the court surface for all to see.

"I only fuss when I feel like I have a reason," he said. "I don't fuss for no reason."

Richey thought he had a reason yesterday in the second game of the first set, when the umpire overruled what looked like a game-winning service winner. Instead of winning the game, Richey lost his serve and went down, 2-0.

"If there are so-called breaks of the game, I got the bad ones," he said.

Richey fought back, though, and eventually prevailed over Fillol, who earlier in the day completed a match with Dick Stockton that was halted by rain Friday night.

Pattison, 36, fell behind Riessen, 4-1, in the first set after Riessen broke serve in the fourth game. Pattison broke back in the seventh game and won a love game on his serve to make it 4-4.

Riessen, 43, went down three break points in the next game. He managed to get a forehand return on a shot that looked like a winner, but Pattison was waiting at the net and put it away with a cross-court smash to break Riessen for the second time and go up, 5-4. Pattison served a love game to win the first set.

"After I broke him the first time, I don't know -- he got a little despondent," Pattison said.

Pattison went up, 4-1, in the second set when he broke Riessen in the fifth game, but Riessen broke back and held to move to 4-3. Pattison held his next two serves to win the match.

Riessen and Sherwood Stewart defeated Tom Gorman and Stockton, 6-3, 7-6 (7-3), in a round-robin match that had been postponed Friday night.

In a rematch of the Wimbledon 35-and-over men's doubles final, Colin Dibley and Fillol will face Riessen and Stewart for the doubles championship here Sunday. Dibley and Fillol won the Wimbledon title, 6-3, 7-5.

In the semifinals yesterday, Dibley and Fillol struggled to a 6-2, 6-7 (8-6), 6-2 decision over Bob Lutz and Ray Moore. Stewart and Riessen advanced by beating Pattison and Richey, 6-2, 6-4.