Tomba Grows Up, Still Goes Down Fast : Skiing: Italian wins giant slalom, the World Cup opener, after an off-season of more work and less play.

An older Alberto Tomba is also wiser.

The Italian skier, who won two gold medals in the 1988 Winter Olympics as a brash, high-living 21-year-old, showed Saturday that he is ready to repeat this performance in February by winning the first World Cup race of the season.

Tomba, who will turn 25 on Dec. 19, is still a free spirit, but when it comes to ski racing, he’s all business--and on a year-round basis.

In the past, he has been criticized for playing too hard in the off-season, but after winning the giant slalom with a come-from-behind second run, Tomba said: “This summer, I trained very hard. Before coming here, I had 50 days of ski training and 40 days of physical training. I am very serious about winning.”

Asked if he is more serious about retaining his Olympic titles than winning his first World Cup overall championship, Tomba said: “It is difficult to look that far ahead. Of course, I want to win at Albertville (France, site of the 1992 Games), but it is best to just look at the next race.”

That will be a slalom at Park City today, when Marc Girardelli of Luxembourg, the four-time World Cup overall champion, gets a chance to redeem himself after failing to finish Saturday’s first run.

“I just caught my arm on a gate and fell,” said Girardelli, who underwent surgery on his left knee last summer. “But I am OK, and the knee is strong.”

Girardelli’s spill took some of the pressure off Tomba, who was second to Paul Accola of Switzerland by 0.45 of a second after the first run.

Between runs, Tomba did two things. He shaved off his stubbly beard--”I did it two years ago between runs in a race at Alta Badia (Italy) and I won,” he said--and he called on his maturity and experience.

“I skied a tactical race,” he said. “In the past, I might have been too aggressive. But today, I did not take big risks at the beginning, then I skied fast at the end.”

He skied fast enough on this cold but sunny day in the Wasatch Mountains to post a total time of 2:05.62, edging Accola by 0.14, and inspired three other Italian racers to finish among the first six.

The top American was Joe Levins, who placed 21st, two slots ahead of teammate Matt Grosjean. The best U.S. giant slalom skier, Jeremy Nobis, had an apparent top-three first run almost on the scoreboard when he hooked a ski tip two gates from the finish and fell.

Said Nobis: “I was smokin’ and I truly don’t know what went wrong. I had it, man. I was going to win today. I knew if I skied my best, I could win. I blew it.”

Skiing Notes

Alberto Tomba said he dedicated his race Saturday to the late Rudi Nierlich, who was killed in a car crash last May, and also to Tomba’s sister, Alicia, who recently turned 15. . . . Nierlich, who was 25, won two gold medals in the 1989 World Championships and repeated in the giant slalom at the World Championships last February.

With prize money now allowed on the World Cup circuit, Tomba earned $15,000, over and above contract payments from suppliers. If he wins today, he will get another $15,000 plus the $15,000 that will go to the racer with the top combined placing for the two days. . . . A new World Cup scoring system is being used this season, with points awarded to the top 30 placers, instead of 15, and 100 points going to the winner, instead of 25.

This was the U.S. Ski Team’s first competition under its new Alpine program director, Dennis Agee, formerly of Mammoth Mountain. . . . Mitja Kunc, one of Yugoslavia’s top racers, was listed as skiing for Slovenia. He fell on his first run.