Wimal Weerawansa, who broke away from the Marxist nationalist Janatha Vimukthi Peramuna to join the ruling United People's Freedom Alliance of president Rajapaksa won 280,672 preferences from the Colombo district.
Ranil Wickremesinghe, from Sri Lanka's main opposition United National Party, trailed third with 230,957 preferences.
Colombo and Gampaha, where president's brother Basil contested are the most populous districts.
In Gampaha UNP's deputy leader Karu Jayasuriya was upstaged by newcomer popular television actress Upeksha Swarnamalee who polled 81,350 preferences to Jayasuriya's 60,310.
The district list was topped by Ruwan Wijewardena, another young candidate with 88,850.Sri Lanka's former military chief Sarath Fonseka now facing a court martial after running for presidential elections in January came on the top of the list in Colombo from his party, the Democratic National Alliance, formed with the JVP.
The party won two seats from Colombo. Sri Lanka's world cup winning cricket captain Arjuna Ranatunga who contested from the same party from Kalutara, a district south of Colombo was also returned to parliament.
The DNA won five seats and is due to get another from the so-called national list.
Sanath Jayasuriya, another popular cricketer topped a district list in Matara in the south of the country representing the UPFA.
A Buddhist priest Athureliye Rathana was also elected from the Gampaha district representing the nationalist-religious Jathika Hela Urumaya, which is part of the ruling UPFA coalition.
President Rajapaksa's son Namal topped the list in the family home electorate in Hambantota, upstaging another brother of the president, Chamal, who came in third place.
The ruling UPFA has so far won 117 seats and the UNP 46 seats with results of two districts not declared due to election malpractices, which may be re-polled.
The Tamil National Alliance, which contested mainly in the island's Tamil dominated north, has won 12 seats so far.
Sri Lanka has a 225-seat legislature where 196 seats are directly contested and the rest allocated proportionally on the basis of total votes.
The ruling UPFA has been pushing for a two-thirds majority (150 seats) to allow it to change the constitution.