No skier has won three titles at a single world championships since France's Jean-Claude Killy swept four races in 1968, but Ligety will have a shot when he races his best event, the giant slalom, on Friday.
Ligety had won gold in the super-G in Schladming last week, and now has three career world championships to go with his gold medal in the combined at the 2006 Turin Olympics in Italy.
"It's definitely somewhat of a surprise," he said. "I haven't really had success in super-combined in years, so to finally get a win again the last time I won was in the Olympics in 2006 it's a long time coming."
The super-combined includes one run of downhill and one of slalom, and Ligety was sixth after the downhill portion of the race, another indication of how far he has come in the speed events over the years.
But Ligety is a slalom specialist by nature, and he grabbed the lead from Croatia's Ivica Kostelic with a tremendous slalom run that turned out to be the fastest of the day. It held up over the last five skiers including fellow Olympic and world champion Askel Lund Svindal of Norway and overall leader Romed Baumann of Austria.
"I just tried to ski as smart as I could," Ligety said. "I tried to have a solid run the whole way down and not make too many mistakes. Seeing the green light at the bottom [indicating a clean run] was a really sweet feeling."
Svindal did not finish neither did Austria's Benjamin Raich, a serious slalom threat and Baumann wound up third, behind Kostelic, who was a whopping 1.15 seconds behind Ligety's final time of 2:56.96.
Ligety becomes only the third American to win double-gold at a world championships.
Bode Miller did it in 2003 and 2005, while Lindsey Vonn did it in 2009 and Andrea Mead-Lawrence did it in 1952.