Congress candidate Chittem Ramamohan Reddy on Tuesday won the Makthal constituency by-poll in the Andhra Pradesh assembly.
Reddy trounced his nearest rival by 40,124 votes.
The election was necessitated by the death of his father Chittem Narsi Reddy, who was killed along with his younger son and nine others in a Maoist attack at Narayanpet on Independence Day.
The Telugu Desam Party, Telangana Rashtra Samithi, Communist Party of India and the Communist Party of India-Marxist did not field candidates.
However, five independents, the Bahujan Samaj Party and Janata Party candidates joined the poll fray. They all forfeited their security deposit.