Three rapes committed against the same victim within one hour occurred in a “single occasion” for purposes of one-strike sentencing under Penal Code section 667.61. All three rapes occurred within an hour while both the victim and the defendant remained in the victim’s apartment. The only movement was a short distance between her bedroom and the living room, and the defendant kept her under his continuous control the entire time. The rapes occurred within a close temporal and spatial proximity, so the court erred in imposing two life terms, and remand for resentencing was required.