Standing in Jansrud's way in the final was compatriot Aksel Lund Svindal, but the former came out on top for a dream parallel giant slalom debut.
It was the eighth podium for Norway during the last four days of racing in Italy, while it was Jansrud's 11th World Cup race win having claimed five victories apiece in both downhill and Super G.
Surprisingly, some early favourites also made early exits with Marcel Hirscher, Ted Ligety and Felix Neureuther failing to finish in the top-eight.
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And that cleared the way for Andre Myher of Sweden to claim the final step of the podium after being German Dominik Schwaiger in the small final.
Meanwhile, there was also plenty for the home fans to shout about as Massimiliano Blardone, who was not even expected to be among the 32 starters but thanks to a strong showing in Sunday’s giant slalom earned a bib for the race, ended up in sixth place, the highest finish for an Italian.
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