German Felix Neureuther, who was second after the first run, had an acrobatic fall on his second turn but continued to ski and ended up 27th.
Hirscher won the slalom World Cup title last season as well as his second consecutive overall title. It looks as if he remains in top form ahead of the Olympics in Sochi.
He said he was especially happy to win in Levi, a course that he has struggled on in the past, but tried to play down the huge expectations on him.
"I'm happy right now to be here, to have a podium, to have a victory," he said. "To stand for the 10th time in a row on the podium ... is a really amazing thing but once for sure this row will come to an end, every row comes to an end."
Park City's Ted Ligety, who won the giant slalom opening race in Soelden last month, improved from a slow first run and finished 11th, 1.96 seconds behind Hirscher.
Ligety, who put a lot of focus on slalom in preseason training in an attempt to take a shot at an overall World Cup title, said he needs to improve if that strategy is to play out.
"I feel like in the second run I skied a little bit more like I should be skiing," he said. "But still far from being what I really need to do in slalom.
"I need to be scoring in the top five to top three, so I need to up it in this if that's going to be a meaningful route to getting me enough points," he added.
Matt, 34, said he was happy to be back on the podium.
World Cup luge
In Lillehammer, Norway, Italy's Dominik Fischnaller posted the fastest time in both runs to win the World Cup luge season opener for his first victory on the circuit.
Fischnaller had a track-record time of 49.172 seconds in his opening run and was two one-thousandths of a second away from matching that time in his second heat. His overall time was 1 minute, 38.346 seconds 0.146 seconds ahead of Germany's David Moller (1:38.492).
Reigning world and Olympic champion Felix Loch of Germany (1:38.497) took third.
Chris Mazdzer of Saranac Lake, N.Y. was the top American finisher, placing 14th in 1:39.040.
Taylor Morris of South Jordan (1:39.683) finished 27th.