Sri Lanka's incumbent President Mahinda Rajapaksa was duly declared winner in Sri Lanka's presidential poll here Wednesday, but the defeated candidate vowed to go to court against the final result.

Elections Commissioner Dayananda Dissanayaka said Rajapaksa had won 6,015,934 votes, or 57.88 percent, while his main challenger Sarath Fonseka won 4,173,185 votes, or 40.15 percent.

Fonseka, who was challenging his former boss on behalf the opposition parties, told reporters that the result did not reflect the voter enthusiasm shown towards him in the run-up to the poll. "We will not accept this result. We will petition against it," Fonseka said.

The island's sixth presidential election was held largely free of violence on Tuesday with 14,088,500 Sri Lankans eligible to cast their votes at 11,098 polling stations.

Dissanayaka said the voter turnout was 74 percent.

Rajapaksa called the election two years ahead of schedule to capitalize on his popularity among the majority Sinhalese after ending the island's bloody ethnic conflict.

Fonseka, who commanded the army to defeat the rebels from 2006 to 2009, is equally credited for the victory.