1)
THE BLESSING ON THE PESACH AND THE ZEVACH (Yerushalmi Halachah 7 Daf 71b)
אמר רבי זעירא דלא ברך ברכת הפסח לא פטר של זבח ושל זבח פטר של פסח שהפסח בכלל הזבח
(a)
R. Zeira: The opposite of the Mishnah seems logical - If he recited the blessing on the Pesach, it should not exempt the Zevach (Chagigah); if he recited the blessing on the Zevach, it should exempt the Pesach, as the Pesach is called a Zevach (as the Pasuk states (Shemos 12, 27), "Ve'amartem Zevach Pesach Hu LeHashem - "You shall say, it is a Pesach offering to Hashem'')?
א''ר מנא הפסח עיקר והזבח טפילה
(b)
Answer (R. Mana): Since the Pesach is primary and the Zevach is secondary, one must recite the blessing on the Pesach.
HADRAN ALACH PEREK ARVEI PESACHIM VESLIKA LAH MASECHTA DEPESACHIM