It was the triple world champion's fourth giant slalom crystal globe and the victory on the Podkoren slope, one of his favourites on the circuit, was his fifth of the season.
It rained heavily for most of the second leg, but with a combined time of two minutes and 35.43 seconds, Ligety finished 0.45 ahead of Austrian Marcel Hirscher while up-and-coming Frenchman Alexis Pinturault was third, 0.77 off the pace.
"It has been a rough and intense fight again, it was really tough to keep the skis under control because of the ruts and the wet snow," Ligety told reporters.
"It was exciting and I again took full risks as it's the best way to approach those conditions and win the globe. I really had an amazing season this winter," added the 28-year-old from Park City.
Ligety's achievement equals that of other great giant slalom specialists like Switzerland's Michael von Gruenigen or Alberto Tomba. Sweden's Ingemar Stenmark clinched the giant slalom standings eight times from 1975 to 1984.
Incredibly, since his second victory in Slovenia in February 2009, Ligety has scored points in all his giant slalom races and has had 20 podium finishes in the discipline.
Last year, Hirscher beat Ligety in the discipline's standings after winning the last race at the finals at Schladming.
Only fourth after the first run, Hirscher raised his game in the afternoon to widen the gap on his nearest rival, Aksel Lund Svindal, in the overall World Cup standings.
The Norwegian finished sixth, 1.30 seconds behind Ligety, but now lies 69 points behind Hirscher overall.
With a slalom scheduled on Sunday, Hirscher has the opportunity to increase his lead further before the World Cup finals in Lenzerheide next week.
"I am happy to lose only half a second on Ted this time - not several seconds as has been the case in the season opener in Soelden, yet I must admit that Ted has been amazing this season in the speciality," Hirscher said.
"In tomorrow's slalom I'll apply the same tactics and attack again as hard as possible."
Svindal was not too disappointed with the result and repeated his assertion that Hirscher was the favourite for the overall title.
"I was aiming for a top-six position today, it's my usual level this year in the speciality," Svindal said.
"Of course I'll keep fighting in Lenzerheide to keep it interesting for everybody, the spectators and the racers. But I'm not a dreamer, Marcel Hirscher has been incredibly consistent this season and I think he'll be very difficult to beat."
- Sports & Recreation
- Marcel Hirscher
- Aksel Lund Svindal