Mr Wickremesinghe's United National Party won a total of 106 seats in the 225-member Assembly, falling short of an absolute majority by seven seats but enough to form a government.
Mahinda Rajapaksa's United People's Freedom Alliance (UPFA) came second with 95 seats while minority Tamil National Alliance swept the ethnic Tamil-majority Northern and Eastern provinces with 16 seats.
"Tamil National Alliance emerging as the third-largest party is an important turning point in this election. After this election, Wickremesinghe is all set to become Prime Minister again. On behalf of DMK I extend my greetings to him", Karunanidhi said in a statement.
The former Tamil Nadu Chief Minister said, "with the Tamil National Alliance win in the election we can hope that a situation has arisen for finding a permanent solution to the travails of Eelam Tamils".
"I express my desire that suitable decisions will be taken in the Parliament in which Tamils living in Sri Lanka would lead a peaceful life and have equal rights.", he said.
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