When Roscoe Tanner arrived in Washington last Monday after a long flight from Brazil, he felt so sick that he planned to withdraw from the $125,000 Volve tennis tournament at George Washington University's Smith Center.

He went to a doctor who told him it was nothing very serious -- just a touch of the flu. Armed with a small arsenal of antibiotics and other medications, he decided to play.

And yesterday, he was rewarded. Playing superbly, he beat his old prep school classmate, Brian Gottfried, 6-4, 6-4, in the singles final of "the tournament that won't go away."

The singles final, the main event of any tournament, was played yesterday afternoon to accommodate the scheduling requirements of the Public Broadcasting Service, which televised it nationally.

Ray Benton, tournament director, could not bear the thought of giving up the Saturday evening and Sunday gates and so stretched the tournament out by two more sessions.

The doubles final will be played today with Stan Smith and Bob Lutz taking on Brian Teacher and Bob Carmichael, who beat Sherwood Stewart and Marty Riessen, 6-2, 6-2, last night.

Smith and Lutz deieated Gottfried and Raul Ramirez, 6-4, 4-6, 7-6 (8-6).

Tanner, 27-year-old left-hander from Lookout Mountain, Tenn., who is playing by far the most consistent tennis of his pro career, earned $25,000 for his second tournament victory this year.

He also won the $250,000 Volvo Tennis Games at Rancho Mirage, Calif., four weeks ago, beating Jimmy Connors in the quarterfinals and Gottfried in the final.

Gottfried, who had won at Smith Center the two previous years, collected $12,500 as runner-up.

Tanner poured all of his dwindling energy into protecting a fading second-set lead after Gottfried had delighted an audience of 4,000 spectators with a spirited revival from 0-4 down in the second set.

Gottfried, also 27, got back to 3-4 and had a break point at 30-40 in the eighth game, but Tanner canceled it with his fifth ace, a fuzzy yellow blur down the center line.

After one more deuce Tanner held his serve and closed out the match -- but again only after a struggle -- two games later.

In the second set, Tanner several times felt physically dizzy. By the end of the 86-minute match, he was enervated.

"Even though I won in two sets, it was very, very tight. I still had a cold in my head, and that took away some energy. I was going full speed on every point, my adrenaline was really pumping, and I was getting awfully nervous when he came back in the second," Tanner said.

"I felt that Brian was getting stronger and stronger, and I was losing energy pretty fast. I think if it had gone to a third set, he would have won easily. So I just kept running for every ball, putting everything into winning the second set. I just wanted to hold my serve; that's all I was interested in."

Tanner, who has won 17 of 20 matches he has played in Colgate Grand Prix tournaments so far this season, came here after playing an eight-man round-robin tournament in Brazil last week, and caught a cold on the flight from Rio de Janeiro to New York.

"By the time I got to New York, my ears were clogged, I had a sore throat, and my stomach felt pretty bad," he said. "After practicing Tuesday, I thought I would default. I told my wife that I was going to."

But a tournament official arranged an appointment for Tanner with Dr. Stephen Haas, the tournament physician, before his scheduled first-round match Tuesday.

"He checked me over and said I didn't have a fever," Tanner said yesterday. "He gave me a bunch of different pills to take and said, 'I think you can play.'"

The doctor was correct.

"Normally everybody expects him to serve well, but today he just did everything well.I had no answers for him," Gottfried said.

"I wasn't upset with the way I was playing. I had some break points early, and I tried a few different things on them. I took chances on some returns, played it safe on some others, and got aced on a few.

"So if you're hitting the ball well and you try everything you can do and it doesn't work, the other guy deserves the credit... Roscoe just played too well."

Tanner held from 15-40 in the second game of the match, and broke Gottfried after two deuces in the third game, Gottfried netting volleys on the last two points. That was the only break of the set.

Tanner escaped four break points as he served at 4-3, Gottfried twice missing passing shots by a couple of inches.

Gottfried got to the fourth break point with a splendid backhand crosscourt from deep in the corner, but Tanner brushed it aside with a crackling service winner. A backhand return wide gave Tanner the advantage, and he cashed it in with another crucial ace.

"That was a huge game, a giant game, for me," Tanner said.

"If you're up 40-0 and serve an ace, it could be just that the other guy wrote the game off. But if it's a tight game, and you know he's fighting hard for it too, and you come up with an ace to blow away the point, that kind of demoralizes the other guy."

Tanner broke to a 4-0 lead in the second set and seemed headed for a rout. But Gottfried started to get used to the pace of his first serves. He returned better, and began to force Tanner back from his dominating position on top of the net with a few of the offensive lobs he had tried earlier but executed poorly.

By the time he had clawed back to 3-4, Gottfried was dancing behind the baseline as he awaited Tanner's serve, looking eager and relaxed. He knew he had a chance. But when his point for the break to 4-4 came, Tanner aced him again.

Gottfried kept fighting, holding serve easily for 4-5 and getting to 30-all as Tanner served for the match.

A netted backhand got Tanner to match point. He missed his first serve, but came barreling to the net behind his second delivery.

Gottfried flicked another lob. Tanner leaped and just got enough of his racket on the ball to snap a back-hand overhead on the sideline, inches out of Gottfried's reach.

"I thought I had missed the ball. I didn't hit it very well and thought it was going wide," Tanner admitted. "It was a good lob. I just took a leap and kind of flipped at it. I was lucky."

Then again, he was lucky to be playing at all. CAPTION: Picture 1, Roscoe Tanner jumps for $25,000 worth of joy after final point in victory over Brian Gottfried in Volvo tennis tournament. By Richard Darcey -- The Washington Post; Picture 2, Brian Gottfried tries to regain his concentration as he stands near a scoreboard that shows Roscoe Tanner leading, 4-3, in second set after winning first, 6-4. Tanner won, 6-4, 6-4. By Richard Darcey -- The Washington Post