Stangassinger, who also won on the Ganslern piste in 1994 shortly before taking gold at the Lillehammer Games, posted a time of 1min 44.27sec. "There are a lot of skiers who can win in Nagano. Let's wait and see what happens," he said. "A victory in Kitzbuhel is just as important as a gold medal in either world championships or Olympics."
Stangassinger's compatriot and last year's World Cup slalom champion, Thomas Sykora, was second in 1:44.35, while Norway's Ole Christian Furuseth made his first podium appearance of the winter with third place in 1:44.42.
Stangassinger continues to lead the slalom standings on 383 points ahead of Sykora on 340 and Norway's Hans-Petter Buraas.
The victory allowed the all-conquering Austrian men's team to beat the Swiss men's 1986-87 record of 18 wins in a season. The Austrians have won 19 of the 25 races staged so far.
The former world and Olympic champion Alberto Tomba missed out on the chance of his 50th World Cup win when he straddled a gate during the first run. The 30-year-old Italian, who was first out of the starting hut, blamed a damaged ski.
In Cortina d'Ampezzo, Italy, Martina Ertl celebrated a record while Deborah Compagnoni saw her giant slalom run come to an end. Winning her seventh World Cup giant slalom, Ertl replaced Irene Epple as Germany's leading winner at the event, while Compagnoni failed for the first time in over a year to reach the podium. Ertl won by a huge margin of 1.55sec over team-mate Katja Seizinger.
Compagnoni, the Olympic and world giant slalom champion, was placed a disappointing ninth following the first run, but posted the second-fastest time in the final run to end up fifth.
Despite Ertl's victory, Compagnoni stays on top of the World Cup giant slalom standings with 505 points to second-placed Ertl's 411.