The victim was admitted to the hospital and her condition was stable, police said.
The woman, who got married eight months ago, came here a week ago, and was staying with her in-laws, they said.
The accused started stalking her when she set out to visit her parents' house in Purushottapuram this morning, and entered the autorickshaw which she had taken.
According to preliminary probe, the victim knew the accused, and he had been harassing for the last four years.
They had a heated argument, and the accused stabbed her with a knife and fled, police said.
As she was yet not able to speak, police did not know the person's identity.