Reference Cornelius: Was saved before or after he was baptized?
And the answer is: Yes.
As I said, Baptism is one of the means of salvation. The Catholic Church agrees with Scripture in seeing that there are various channels by which Our Lord conveys to us the fullness of redemption. As Scripture says, we are saved:
So my answer would be: Cornelius was saved by being incorporated into Christ by faith, by Baptism, and by whatever other means provided by Our Lord for his redemption.
When asked "Are you saved?" the best answer is "I was saved; I am being saved; and I hope that in the end I will be saved." That goes for Cornelius, too. It's not a one-shot deal. God has 10,000 ways: He is a genius at Salvation, an absolute genius; and His ways are above our ways as the heavens are above the earth, and His thoughts above our thoughts.