A woman was stabbed to death by a female acquaintance in Mount Eden, police said yesterday.

Diana German, 20, and the victim, Saoni Casado, 21, got into a fight outside German's apartment on Morris Avenue near East 173rd Street late Sunday.

Sources said German whipped out a knife and stabbed Casado in the chest. Casado was rushed to Bronx Lebanon Hospital, where she died shortly after midnight.

German was charged with murder, police said.