When Phil Mahre pushed off on the second run of the men's slalom today, he knew that the race of his life would end with an Olympic gold medal. The world's best skier, Ingemar Stenmark, could be beaten.

"I hit the third or fourth gate -- I don't remember which -- and carried the pole a couple of gates," he said. "I lost a lot of time there. A while later I went straight, then sideways, and nearly had to stop."

Mahre was able to recount all that with a smile, for while he failed to catch the incomparable Stenmark for the gold, the silver medal he did earn represented the highest American men's alpine finish in 16 years -- and it all happened within a few hundred yards of the slope where he suffered a broken leg that many thought might keep him from these Games.

After the first of the two runs on a course most fans could see from beginning to end, the 22-year-old Mahre was in the lead. He was first down the mountain -- the only American who made it more than halfway -- and led a Swiss and an Austrian by .39 second and Stenmark by more than a half second.

The Americans were joyous, chanting Mahre's name whenever someone would scurry under the finish line with a slower time. The Swedes were quietly cocky.

"He (Stenmark) will not be beaten," said a man waving a Swedish flag attached to a large twig.

But Stenmark was not in ideal position. The giant slalom winner ended the first run in fifth place, which meant he would be first off when the course was redesigned for the second run. The others would know in advance the time to beat.

Just before the second run, Stenmark jumped to fourth place without lifting a ski; Bojan Krizaj was disqualified. He had been given a second try after protesting that a misplaced pole had caused him to veer off course.

So the oldest skier in the competition, 30-year-old Christian Neureuther of West Germany, would be the first to run of the top five, the ones who figured to have any chance for a medal. Numbers 6 through 37 would follow the top five, more than half the field having failed to complete the first run and qualify for another.

And Neureuther was excellent, with a run of 50.77 seconds. But Stenmark, twisting through the 60 gates (six fewer than the first course), was swifter by .40 second.

"I didn't know that it would stand up," Stenmark said. "I had a good second run -- but I knew Phil had a good chance, too."

Mahre had the only chance.

"I went for it right at the first," Mahre said. "But when you have problems like I had they carry over (because of the short distances between gates)."

Could he have beaten Stenmark with fewer problems early"

"I doubt it," he said. "Actually, I lost most of my time in the middle of the course."

In a sport where hundredths of a second are vital, Mahre was a full second -- and small change -- slower than Stenmark on their second runs.

"He always puts two good runs together,"said Mahre. "Most of us have one good run, then lose concentration. He does well from one run to the next -- and all season long."

"I didn't make any mistakes," Stenmark said, "but I think I could have been faster."

That was as expansive as Stenmark would get. In keeping with his stoic nature, he replied to a question about whether he regretted not training for the downhill -- and possibly winning three gold medals -- with:

"I feel good."

Never enthusuastic about it, Stenmark had quit the downhill after a serious practice injury and vowed never to return. He repeated that pledge today. So Jean-Claude Killy and Toni Sailer are the only men to win every alpine event in the same Olympics.

What will Stenmark do to celebrate his two golds?

"Nothing," he said.

Has he accomplished all his goals?

"Yes."

Mahre became the first American man to win an alpine medal since Billy Kidd captured a silver and Jimmy Heuss a bronze in the '64 Games. Mahre's was the third silver medal for the U.S. in these Games and its ninth medal in all.

Also, by finishing in the top 15 in both the downhill and giant slalom, Mahre won the combined championship the International Ski Federation awards each year. It considers the Olympics as the title event this season.

Mahre suffered a badly broken leg on the giant-slalom course here near the end of the 1979 season. He has mended enough to wonder why anyone would ask if he had doubts about competing at this level.

He also has not trained long for the slalom.

"Just a day and a half the last three weeks," he said. "But if you train for the giant slalom, the slalom comes easy. And it comes naturally for me anyway."

Mahre's twin brother, steve, Billy Taylor and Pete Patterson all fell near the top of the hill. Said Steve in reply to a question about whether his injured ankle hurt: "I didn't go far enough to get hurt."

In the only other final event today, the Soviet Union won its fourth straight gold medal in the 4x7.5 sklometer biathlon, with a time of 1 hour, 34 minutes 4.27 seconds. East Germany was second, 53 seconds behind, and West Germany third.

This is the fourth time the event has been held and the Soviets have won every one. Today they hit every target. The East Germans missed three.

The United States finished eighth.