Thane Ad-hoc district judge RS Patil (Bhosale) also slapped a fine of Rs 1,000 on the convict Hamid Rashid Qureshi alias Ammu.
He was found guilty under section 397 of the Indian Penal Code (robbery, or dacoity, with attempt to cause death or grievous hurt).
The court was told that Qureshi was externed from the limits of Thane but he came down to the city and indulged in the crime.
Prosecutor Rekha Hiwrale told the court that on the night of August 29 Qureshi chased the victim - Shabina Latif Kazi - who was travelling on a two-wheeler with her cousin - and threatened her and snatched her golden chain, worth Rs 9,000.
"The prosecution has proved alleged offence against accused punishable under section 397 of the IPC, beyond all reasonable doubts.
"Taking into consideration the nature and gravity of the alleged offence, pains suffered by the victim, who is poor woman and as accused has committed said offence at night on public road, some severe punishment is required to be inflicted on accused," the judge noted in his recent order and sentenced Qureshi to seven years rigorous imprisonment.