53-year-old Shravan Rathore allegedly committed the crime in a rented flat in Govindpura area and he owns a house in another locality of the city.
The 13-year-old victim is the daughter of Rathore's domestic help, who had gone to Ahmedabad late last month to meet her in-laws, they said.
In her absence, Rathore allegedly called the victim to his house and offered her a cold drink laced with sedatives following which she became unconscious. He kept her in captivity for two days and repeatedly raped her, they said.
On her return, the woman, a widow, filed a police complaint on the basis of which Rathore was arrested yesterday.