Hirscher turned in a two-run time of 1 minute, 51.75 seconds, 0.30 seconds faster than fellow Austrian Mario Matt.
The victory gave Hirscher 855 points for the season. Aksel Lund Svindal was in second with 729 points followed by Ted Ligety of the United States.
Manfred Moelgg of Italy took third Sunday with a 1:52.37 and was followed by Croatia's Ivac Kostelic. Moelgg led after the first run but swerved on the second run and lost enough time to come in 0.62 seconds behind Hirscher.
David Chodunsky was the top American finisher with a 1:53.87 that was good enough for 10th place.