Frosinone beat Palermo 2-0 in the second leg of their playoff final on Saturday to earn promotion back to Serie A after a two-year absence.
Raffaele Maiello scored early in the first half to erase a 2-1 deficit from the first leg.
That would have been enough to see Frosinone through because they finished higher in the season table, but Camillo Ciano sealed it in stoppage time by finishing off a counter-attack.
Frosinone, located south of Rome, joins Serie B champions Empoli and runners-up Parma in the top flight next season.
In the Canaries' only previous season in Serie A, Frosinone finished 19th in 2015-2016.
Frosinone opened its Benito Stirpe Stadium this season more than 40 years after construction began, including 30 years of inactivity.