Congress candidate KSK Rajendran, backed by Tamil Nadu's ruling DMK, on Friday won the Madurai West by-election, defeating the AIADMK by over 31,000 votes.
Rajendran polled 60,933 votes while Sellur K Raju of AIADMK got 29,818 votes.
DMDK candidate T Sivamuthukumaran came third, polling 21,272 votes.
The election was held on Tuesday following death of AIADMK legislator SV Shanmugham, who represented Madurai West in the state assembly. The counting of votes began on Friday morning.