Sri Lanka was to swear in its new president Friday after incumbent Mahinda Rajapaksa lost the previous day's polls to his last-minute challenger and former health minister Maithripala Sirisena, according to dpa. Sirisena, 63, won 51.28 per cent of the vote, to Rajapaksa's 47.62 per cent, elections chief Mahinda Deshapriya said. Sirisena was due to be sworn in later Friday. He called on his supporters to celebrate peacefully, after voting went ahead with less violence than feared. "We should not only to refrain from physically harming others, but also avoid causing any mental anguish," he said. Supporters of Sirisena lit firecrackers as the first counts showed him winning. Rajapaksa's spokesman Wijeayananda Herath said the outgoing president "thanked those who supported him and said he was accepting the people's verdict." About 75 per cent of the 15 million registered voters turned out. Sirisena's victory was attributed to support from a wide range of opposition and minority parties, including a Tamil party formerly allied with the rebels of the Liberation Tigers of Tamil Eelam, who were defeated by the military in 2009, and a Muslim party. Sirisena was particularly successful in the north and east of the country, where the Tamil ethnic group is concentrated. He lost in some southern areas, but by narrower margins. Sri Lanka's presidential elections are decided by the nationwide total, with the winner needing 50 per cent plus one vote. Troops were deployed in and around Colombo, but there was little violence reported since the poll ended late Thursday. Police Inspector General NK Illangakoon urged people to stay calm. Rajapaksa called elections early, with two years left of his six-year mandate. His United People's Freedom Alliance has held the presidency for the last two decades.