Cleone and some maidens invite Ermione to go hunting with them (Chorus: "Dall'Oriente l'astro del giorno" / "The sun is rising in the east"), but she is angry that Pirro has forsaken her and is courting Andromaca. Pirro arrives, expecting Andromaca, but she is not there. He sees Ermione and tries to escape, but she detains him and they quarrel (Duet: "Non proseguir" / "Say no more"). They are interrupted by a chorus of grandees, who announce the arrival of Oreste ("Sul lido, di Agamennone il figlio, Oreste, è giunto" / "On our shores Agamemnon's son Oreste has landed"), to Pirro's alarm and Ermione's delight. Pirro recovers and leaves to arrange Oreste's reception; meanwhile, Ermione fears that Oreste's arrival will only lead to the marriage of Pirro and Andromaca.