The woman, a widow, is battling for life at a government hospital here, police said today.
The accused Palanivel, a vegetable vendor, of Malliyakari in the district was detained by the local people and handed over to police who arrested him and slapped a rape case.
According to police, the woman was living alone at Gopalapuram in Malliakari.
Around midnight last night, Palanivel, who has two wives and four children, went to the victim's house and asked for water, but she refused.
Suddenly, he forced his way into the house, allegedly raped her and bit her private parts.
Local residents called an ambulance and rushed the woman to Attur Government Hospital from where she was shifted to Mohan Kumaramangalam Medical College Hospital here.
Doctors said the condition of the woman was critical.
Flashback: When bikini babes set a new world record in Australia
Photos: 'Rock On 2' stars Farhan, Shraddha on 'Yaaron Ki Baraat'
Photos: Ajay Devgn launches 'Shivaay' comics at Mumbai Comic Con
Photos: WWE star Sheamus and John Abraham clash in Mumbai
Umesh Yadav's birthday: Indian cricketers and their tales of struggle