Kroldrup met D'Agostino's free-kick with a tame header which Rosati saved and Gilardino then headed another cross from the same player wide.
Centre-half Stefano Ferrario tested Viola keeper Sebastien Frey but failed to find the net. Later, Rosati denied Gilardino from inside the six-yard box.
After the interval, Gilardino fired wide from distance before Kroldrup had the ball in the net and Young substitute Adem Ljajic failed to hit the target with a free header when well placed to meet Manuel Pasqual's cross and Cerci was equally wasteful when he failed to convert D'Agostino's low cross.
Rosati made one final impressive save to deny substitute, Khouma Babacar, in the last minute.