Patil is a resident of Gala Nagar in Nalasopara (East) and hails from a well-off family, police said. He has studied up to Class 10 and does odd jobs for a living.
Police said the victim met Patil during one of her visits to her aunt who lives near Patil's home.
The girl lives with her mother and brother.
The victim, in her statement to the police, said Patil befriended her and promised to marry her when their relationship became physical. However, when he refused to marry her, the girl confided in her family.
“Her family lodged a complaint with us on Tuesday. Patil was arrested the same day and both were sent for a medical examination, reports of which are awaited. Patil was booked under provisions of the Indian Penal Code and Protection of Children from Sexual Offences Act,” said a police officer.
On Tuesday, Patil was produced before a Thane court which remanded him in police custody until May 15.