The Real Madrid stopper praised his teammates after they held their opponents to a 0-0 draw, but believes that they are lucky to be in the final.
"This generation is unforgettable. Lucky for the Spanish to have seen another win and we're in the final," Casillas told Tele-5.
"The truth is it was very difficult to win. Italy had made an excellent approach. We tested [Gianluigi] Buffon as well but they placed us in trouble.
"The thing about the shoot-out is it is a lottery and we have been lucky enough to win. My teammates have had full success on the penalties and they [Italy] missed one."