Hirscher, the six-time defending overall World Cup champion, finished with a combined time of 2min 37.30secs with Norway’s Henrik Kristoffersen second in 2:38.18 and German Stefan Luitz third.
Hirscher earned his 46th World Cup win and his first since he broke his ankle in training.
“I did not expect to win here. I knew that I was skiing well, but I still thought I was far from the best times,” said the four-time world champion who in February will try to fill the only void on his resume when he goes for gold at the Pyeongchang Winter Olympics.
With the Games on the horizon, Hirscher has pushed himself to return to form.
“It was a hard time for sure,” he said of his enforced absence. “Luckily I am here.
“The last month was very hard. I just skied, skied, skied as many runs as possible to get the speed, to come closer to my teammates. They were kicking my ass every day, that’s the truth (but) I improved myself every day.”
Third after the first leg on the Birds of Prey course, 39 hundredths of a second behind Luitz, Hirscher delivered a flawless second run.
“I said to myself let’s go for it, let’s give it a try, let’s see what come out of it,” he said. “It’s really unexpected.”
Thanks to a few points garnered in a slalom at Levi, and also to the postponement of the scheduled opening giant slalom in Soelden, Hirscher isn’t too far out of touch in the overall standings.
He is in 14th place with 114 points, 135 points behind leader Kjetil Jansrud of Norway, who failed to gain any points on Sunday.
The men’s World Cup resumes next week in Val d’Isere, France.