CALGARY, FEB. 20 -- There are rare occasions when a performance lives up to the considerable expectations given to something like the Winter Olympics. Tonight, Brian Boitano presented the United States with its first gold medal, a prized, impeccable one in men's figure skating that defeated hometown world champion Brian Orser of Canada.

There were three one-time world titlists at the Saddledome in Boitano (1986), Orser ('87) and Alexander Fadeev ('85) of the Soviet Union. Each skated nervelessly and almost cleanly, with just the slightest mistakes. But Boitano earned higher marks than Orser on what amounted to a split decision, from five of the nine judges.

Orser received his second Olympic silver medal, the first coming in 1984 when he lost to Scott Hamilton, also of the United States. Fadeev's errors relegated him to fourth place; his 18-year-old teammate, Viktor Petrenko, ushered in a new regime of Soviet skaters by taking the bronze.

The United States has won five gold medals in men's figure skating history. Canada never has won the gold.

Boitano, skating first in the final group, performed to Carmine Coppola's score of the epic "Napoleon." Once accused of skating without art or feeling, Boitano found expression in the romantic military piece. He accomplished what was quite simply the performance of his life, almost unflawed with eight arcing triple jumps. There was just one appreciable error, when he landed momentarily on two feet.

"My feeling was that I had done what I came here to do. That was it. I did it," he said.

The routine also was emotionally complex and riveting, with eight difficult dramatic sections and changes in music, including a 15-second, lingering spread eagle that drew gasps. But Boitano kept himself tightly controlled until the last combination jump and end of the military march.

Then, the banker's son from Sunnyvale, Calif., nearly burst into tears. He threw back his head and clenched his fists to a thunderous and extended ovation.

"I was trying so hard to take one thing at a time and not get excited," Boitano said. "I knew I had to keep control. I didn't break until the end."

All the while, Orser was backstage frantically going through his warm-up moves, hearing it but oblivious. The roar increased with Boitano's marks: five 5.9s out of a possible 6.0 for technical merit, the rest 5.8s. Artistically, he received three more 5.9s, five 5.8s and one 5.7.

"I did it," Boitano said to his coach of 16 years, Linda Leaver. He then strode into the dressing room and collected his things, as if to prove he had skated only for himself.

Fadeev skated next, an uninspired piece that received solid 5.7s. Then came Orser. Skating third in the group meant that Orser knew what he had to do, and had a better chance at gold medal marks, since the judges had reserved a margin of improvement for the world champion. But he also had an agonizing wait backstage listening to the scores and ovations.

Yet Orser, too, skated almost flawlessly, to "The Bolt," a classical piece slightly Russian and militaristic in feel. His loose, flowing style that is so distinctive was fully present, to make it one of the closest Olympic skating events in memory. But Orser had two small mistakes that deprived him of the gold. First, he stumbled out of a triple-flip, not falling, but landing unsteadily and wreching his body. Then, out of caution, Orser knocked a triple jump down to a double late in his program.

That left him with just six triples, one flawed, to Boitano's imposing eight. His marks for technical merit were almost good enough: eight of 5.8 and one of 5.9. Artistically, they were unparalleled, with five of 5.9, three of 5.8 and a perfect 6.0 from the Czechoslovak judge. That tied him with Boitano on the scorecards of judges from Denmark and Switzerland. But the tie breaker was the technical mark, and Boitano took each.

"I'm just disappointed," Orser said. "I didn't win gold medal and that's what I came here to do. I wanted to be Canada's first gold medalist . . . I thought for a moment there I had done it."

Those who skated before the final group were made up of coming skaters, ones who will perhaps be more of a factor in four years. Canadian Kurt Browning tried the unprecedented quardruple toe loop that Orser and Boitano possess but elected not to use here because of the risk. Browning attempted the never-landed jump midway through his program, but fell after 3 1/2 revolutions and placed eighth.

Also in that group were two Americans, 23-year-old Harvard undergraduate Paul Wylie, and 20-year-old Christopher Bowman of Los Angeles. Wylie fell on his first two triple jumps, a flip and an axel, but came back to place ninth. Bowman, a great young showman, had just minor errors in his Hungarian dance to earn slightly higher marks and finish seventh.

The event began three days ago as a virtual draw between the various world champions. Fadeev led after the compulsories, worth 30 percent, over Boitano and Orser in that order. Orser won the short program, worth 20 percent, but Boitano took the overall lead on the strength of his second-place standing in the first two portions.

All of which meant simply this: whoever stood up and skated cleanly in tonight's performances, worth 50 percent of the overall score, would claim the gold medal. They would also claim the unofficial title as the most masterful skater of their Olympic quadrennial.

Orser and Boitano, who placed fifth in 1984, spent years and considerable effort building to tonight's confrontation, which might have been a test of their friendship as well as their skating ability. The two have remained close despite critical comparisons of their opposing styles over an association (they don't like to be called rivals) that began 10 years ago in the junior ranks.

"People have tried to pull us apart," Orser said. "They've tried to make us enemies and rivals. But the fact is we're still very close."

Orser was called an artistic but inconsistent also-ran who finished second in the 1984 Olympics and three ensuing world championships before he finally won the 1987 title. The brilliantly athletic Boitano was consistent, but called too mechanical and wooden, despite his 1986 world title. Each ultimately proved tonight they had remedied those, and it was indeed the Battle of the Brians.