In a tight finish, the Swiss skier put down a stunning second run to pick up her third medal of Cortina 2021, after winning her maiden world title in the Super G a week earlier.
Two-time Olympic champion Mikaela Shiffrin was leading after the first run, but had to settle for silver, as she just missed out on a seventh world title by 0.02 seconds.
Katharina Liensberger of Austria took bronze, just ahead of 19-year-old Alice Robinson of New Zealand.
Gut-Behrami's performance means she becomes the most decorated Swiss woman in world championships history.
“I’ve been struggling a lot in the last years, but this year I was coming back step by step,” she after the race. “I was tired, but I just tried to enjoy.”
Shiffrin was happy with her silver. “I’m actually pretty excited, because the last three [World Cup] GS races, I was losing a lot more time in the second run,” the American said.
“Getting even a silver and being so close and hanging onto a medal … it was really not guaranteed, so that’s pretty cool." - Shiffrin on silver.
There will be more medals up for grabs in Saturday's women's slalom, where Shiffrin is the defending four-time world champion.
You can get a behind-the-scenes at her preparations for the Cortina 2021 event in the Olympic Channel original series Cirque Blanc.