A South African Police Service spokesman said the attempted rapist fled covered in blood screaming and leaving a piece of his tongue on the bed.
Officers who attended the scene at the village of Reitz near Bethlehem in the Free State went to the local hospital where they found the wanted man.
He was covered in blood and was awaiting surgery on his damaged tongue.
Police spokesman Zweli Mohobeleli said: ‘The man attacked her with a knife but she fought back and grabbed his tongue with her teeth and bit hard.
‘She bit so hard that a piece of his tongue came off and he ran away leaving it behind and cops arrested him at the hospital where he had gone to.
‘We collected forensic evidence from the clothes and handed the piece of tongue to the family of the suspect and he will appear before a court very soon’.
The suspect was remanded in custody by Reitz Magistrates Court on a charge of attempted rape.