MONROVIA (Reuters) - Former soccer star George Weah maintained his lead over Vice President Joseph Boakai as more provisional results from Liberia’s presidential election were announced on Friday.

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If current trends hold, they would contest a run-off next month to decide which of them will succeed Nobel Peace Prize winner Ellen Johnson Sirleaf in what would be Liberia’s first democratic transfer of power in decades.

Based on returns from about a third of the country’s more than 5,000 polling stations, Weah has obtained 39.6 percent of votes cast, with Boakai of the ruling Unity Party (UP) at 31.1 percent, the elections commission said.

“We are still confident that there are places that we believe are our strong support ... We are very optimistic that with reports coming in, UP is going to take the lead,” Boakai told Reuters after Friday’s results announcement.

Charles Brumskine, a lawyer, was running third with 9.3 percent.

The final certified results from Tuesday’s poll must be announced by Oct. 25, although the provisional first-round winner is expected to be known in the coming days.

Weah, a striker for Paris Saint-Germain and AC Milan who won FIFA’s World Player of the Year in 1995, came second to Johnson Sirleaf in a 2005 election that drew a line under years of civil war that killed hundreds of thousands of civilians.

He has served in the senate since 2014 for the opposition Congress for Democratic Change.

Boakai, the former head of Liberia’s petroleum refinery company and agriculture minister, has served as vice president since 2006.

Brumskine and the parties of two other candidates have said the vote was marred by fraud and vowed to contest the results. But they have not provided evidence of cheating and international observers said they saw no major problems.

Liberia, Africa’s oldest modern republic, was founded by freed U.S. slaves in 1847 but its last democratic power transfer occurred in 1944.

Johnson Sirleaf’s nearly 12 years in office have seen the country’s post-war peace consolidated, although Liberians complain about poor public services and widespread corruption.