If this afternoon's singles final of the $100,000 VOlvo Classic - Brian Gottfried vs. Bob Lutz - is anything like yesterday's semifinals, you should not plan to attend if you have a weak heart.

Gottfried, the No. 3 seed, eliminated second-seeded Raul Ramirez, 6-7, 6-3, 6-2, in a thrilling matinee match at George Washington University's Smith Center.

But exciting as that was, it couldn't quite keep up with the tingles produced when Lutz, the No. 6 seed, ousted unseeded crowd favorite Tom Gorman, 6-7, 6-0, 6-, in the evening feature.

Gorman had lived dangerously all week, overcoming five match points (including quadruple match point at 2-6 in the final-set tie breaker) against Cliff Richey in the second round, and beating Jeff Borowiak in the quarters even though he only managed to get through two service games without break points against him.

Last night it looked as if he would escape again, even though in the second set Lutz hit with such unrelenting fury that Gorman must have felt like a man in a hailstorn without an umbrella.

Gorman had an advantage point on Lutz' serve at 3-4 in the final set, and got into the net for a breast-high backhand volley.

The ball had "Gorman's first final of the year" written all over it, but he overanxiously put it in the net. That was his golden chance, and it was gone. He grimaced, momentarily pulling the lids down over his Irish eyes.

Lutz put in two good first serves to reach the promised land of 4-4. He hit good returns to set up two break points in the next game and converted the second, forcing Gorman to miss a desperate, reacing forehand.

Gorman did save two match points to the delight of a crown of 4,800 that appreciated his gallant efforts. But the powerful 5-foot-11, 182-pound Lutz poured a big serve down the center and Gorman could do no more than forlornly deflect it.

"It was one of those matches that you can really say came down to one point, I think," said Gorman, gracious as ever in defeat.

"If I make that volley it's 5-3," he said softly."It was an easy volley. I just missed it."

"Tom's like that," said Lutz, 29, a good friend and contemporary of the 31-year-old Gorman. "He comes up with some unbelievable shots, some incredible stuff off the shoetops, and then he misses an easy one."

Lutz, runned-up to Vitas Gerulaitis in the Ocean City International last month, has not won a tournament of any significance since the Tokyo stop on the World Championship Tennis tour in April, 1975.

Gottfied, who has lost only three of 28 matches this year, has already won two tournaments in the 1977 Colgate Grand Prix series: The Towson International in January (where he beat Gorman in his only other semifinal appearance of the year) and the American Airlines Tennis Games at Palm Springs last month. There, he beat Lutz in the third round, 6-3, 7-5.

Lutz has a good career record against Gottfried, but the 25-year-old Floridian has won their last two meetings, at Palm Springs and Wimbledon last summer.

They meet for the $20,000 first prize today at 1:30 p.m. at Smith Center. A delayed tape telecast will be carried by WETA-TV-26, from 5 until 7 p.m.

Gottfried and Ramirez form the No. 1 doubles team in the world. They know each other as well as Siamese twins. In singles, their career record is vistually even - 9-7 in favor of Gottfried - and 11 of their 16 matches have gone to three sets.

Yesterday they ran each other all over the court, sprinting and diving, testing the quickness that both have in abundance.

One would break serve, and the other would promptly lift his game and break right back. They probed each other for 2 hours and 39 minutes, treating the smaller-than-expected afternoon crowd of 3,700 to an absorbing all-court battle.

Twenty minutes after their singles match they reunited and zapped Zeljko Franulovic and Chico Hagey, 6-4, 6-2, to advance to the doubles final.

They will play the winner of the late semifinal pitting Lutz and Stan Smith against Charlie Psasarell and Erik van Dillen. The winning doubles team splits $6,000.

If there was such a thing as a turning point in the Gottfried-Ramirez singles match, which had nearly as many games go against serve (14) as with it (15), it would be the sixth game of the final set.

Ramirez the 23-year-old Mexican Davis Cup star who is the defending champion in the Grand Prix, had served his poorest game of the match to fall behind, 1-3. He missed three of four first serves, double-faulted to 0-40, and was broken at love on a perfect forehand volley by Gottfried, who had him lunging defensivenly from side to side.

But following a repetitive course of events that had been established early, Ramirez broke back in the next game. Gottfried, who periodically had fits with his backhand, punched a low volley long off that side, and then Ramirez forced a driving volley error with one of his patented backhand cross-courts, sharply angled and dipping wickedly as it came over the net.

So now is was 2-3, Ramirez serving to level once again a tense match whoe dominant pattern was the zig-zag.

He put in a good first serve to the forehand and Gottfried crankled a clean winner cross-court. Then he missed a first serve, and netted a low backhand volley off a soft, annoying backhand cross-court angle: 0-30. Ramirez put in another first ball, but Gottfried whislted a backhand cross-hand passing shot by him: 0-40. A deep breath, and another first serve in, Crunch. Gottfried sizzled a back-hand-down-the-line winner for the break to 2-4.