PRESUMPTION OF LEGITIMACY:

     A party in whose favor the legal presumption exists may rely on and invoke such legal presumption to establish a fact in issue. He need not introduce evidence to prove that fact. For, a presumption is prima facie proof of the fact presumed. However, it cannot be over-emphasized, that while a fact thus prima facie established by legal presumption shall, unless overthrown, stand as proved, the presumption of legitimacy under Article 164 of the Family Code may be availed only upon convincing proof of the factual basis therefor, i.e., that the child's parents were legally married and that his/her conception or birth occurred during the subsistence of that marriage. Else, the presumption of law that a child is legitimate does not arise. (Belen Sagad Angeles vs. Aleli 'Corazon Angeles Maglaya, G.R. No. 153798).