With results of 25 constituencies declared, Congress won 12 seats and was leading in three others while DMK bagged one seat and ahead in another as the alliance looked set for a comfortable majority.
After an initial close fight, AINRC managed to win only eight seats, including the Indira Nagar constituency by party founder and Chief Minister N Rangasamy.
AIADMK, which fought the elections on its own, won three seats while an independent emerged the victor in one constituency. AIADMK was also leading in another seat.
In Karaikal South constituency, five-time DMK MLA A M H Nazeem lost to AIADMK's K A U Asana by a slender margin of 20 votes.
Congress heavyweight E Valsaraj lost to independent V Ramachandran in Mahe.