The 25-year-old won her first overall Crystal Globe last season and has put down a marker for her rivals in the first race of the winter by triumphing in the giant slalom.
She led the field by 1.42 seconds after Saturday's first run and clinched the win over Mikaela Schiffrin in the second. The American finished 1.44 seconds off top slot.
Gut told the official International Ski Federation (FIS)
website that she had been a little nervous before the first race as defending champion.
"It's always special in Soelden," she said. "It's a beautiful day. I love the slope. I have to enjoy that. I just tried to ski."
Schiffrin was upbeat after the race, telling the FIS site: "I definitely like second. I like first better, but it is nice to start off on this foot and it was really a tough day for a lot of girls."
Schiffrin is still only 21 and is tipped to be one of the main contenders for overall title as she adds the downhill to her disciplines in an effort to be as dominant in the speed event as she has been in the slalom.
After one giant slalom race, Gut leads Schiffrin by 20 points with Italian Marta Bassino in third and Austrian Stephanie Brunner in fourth.
Last year, Gut was involved in a close battle with Lindsey Vonn until the American suffered a late season injury.
After struggling with three serious knee injuries in four years, Vonn decided to sit out the giant slalom in Soelden and will instead focus on the speed events.
Competitors in the women's giant slalom have a break between races, with the next contest during the US Thanksgiving weekend in Killington, Vermont. It will be the first World Cup held on the East Coast since 1991.
All eyes will be on Austria's Marcel Hirscher, who has won five successive overall titles, and three each in both the giant slalom and slalom. He has won the Soelden opener four times in the past five years.
Hirscher will face a challenge from American Ted Ligety, whose 2015-16 season was cut short by injury.