Judges 16:24
And when the people saw him, they praised their god: for they said, Our god hath delivered into our hands our enemy, and the destroyer of our country, which slew many of us. And when the people saw him, they praised their god: for they said, Our god hath delivered into our hands our enemy, and the destroyer of our country, which slew many of us.
When the people saw Samson, they praised their god because they believed their god had delivered their enemy Samson into their hands. The god they received that praise was Dagon. In that praise they called Samson the destroyer of their country.
By destroyer of their country they meant that he had killed many of them. Their praise expressed their belief that their god had defeated Israel's champion. Their celebration wrongly treated Samson's capture as proof that Dagon was superior to the God of Israel, so the conflict had become a contest between Dagon and Jehovah.