The ruling AIADMK on Wednesday emerged as the winner at Sankarankoil with its candidate S Muthuselvi winning the byelection with a record margin of 68,765 votes.
All the other contestants, including those from the DMK, MDMK and DMDK, lost their deposits.
While Muthuselvi secured 94,977 votes, DMK's Jawahar Suryakumar got 26,220 votes followed by MDMK's Sadan Thirumalaikumar with 20,681.
DMDK candidate K Muthukumar was pushed to the fourth place with only 12,144 votes. DMDK was an ally in the Assembly election last year but later broke its ties.
Sankarankoil comes under Tirneveli district, which is facing the heat over the Kudankulam nuclear plant. The bypoll was necessitated following the death of state minister, AIADMK's C Karuppasamy, in October 2011 due to ill health. The bypoll, across 242 polling booths on Sunday, saw a voter turnout of 77.5 per cent.
