Ligety's first-run time of 1 minute, 17.10 seconds provided Ligety with a nice cushion that he parlayed into a 2.04-second win over second-place Marcel Hirscher of Austria.
"It's tough to go out in the second run when you're winning by 2.40," Ligety said. "You don't want to lose all that speed and not win but you also don't want to be so relaxed that you make big mistakes."
Ligety turned in a winning combined-run time of 2:37.27 on the icy, bumpy course. Thomas Fanara of France placed third with a 2:40.54.
Ligety remained in second place behind Aksel Lund Svindal of Norway in the overall World Cup point standings. Svindal finished in 12th place Sunday.
The win was Ligety's 14th in the giant slalom and tied him for fourth on the all-time win list for the demanding event with Austrians Benni Raich and Hermann Maier. Italy's Alberto Tombo has 15 GS wins and Swedish legend Ingemar Stenmark leads the list with 46.