Leporello stands guard as he waits for his master, Don Giovanni, and complains about his life as a servant (Notte e giorno faticar). He is the lookout as Don Giovanni sneaks into the Commendatore’s house to attempt to seduce his daughter, Donna Anna, in disguise. Don Giovanni enters, being followed by Donna Anna, who insists that he unmask himself, and eventually screams for help. The Commendatore enters and forces Giovanni into a duel, for the honor of his daughter. Don Giovanni kills him and flees with Leporello. Donna Anna, having run for help, returns with her fiancée, Don Ottavio, only to find her father murdered. Devastated, she demands that Don Ottavio find vengeance against the man and bring him to justice (Ma qual mai s’offre).
In a square in Seville, Giovanni and Leporello come across a woman who is declaring her revenge about being betrayed by a former lover. Giovanni attempts to flirt with her, only to discover that she is Donna Elvira, his former lover, and she is