Prime Minister Ranil Wickremesinghe's United National Party (UNP) came second on Sunday with 82 seats while the third place went to proxies of Tamil Tiger guerrillas, who secured 22 seats.
No party crossed the magic number of 113 needed to enjoy an absolute majority in the 225-member legislature, pointing to either a minority government or a shaky coalition.
President Chandrika Kumaratunga's Freedom Alliance won 4.22 million votes, or 45.60% of the total votes polled on Friday at an election held under a system of proportional representation, official results showed.
Wickremesinghe's UNP garnered 3.5 million votes or 37.83%.
Nine seats went to a party of all-clergy Buddhist monks while a Muslim party won five seats, with two other Tamil parties getting one each.
Kumaratunga called the election nearly four years early after accusing her rival Wickremesinghe of being too soft in dealing with Tamil Tiger rebels.