President Goodluck Jonathan has a strong lead in Nigeria's presidential election, taking almost twice the number of votes.
Results from 30 of 36 states showed the incumbent had won 20, while former General Muhammadu Buhari had nine.
Mr Jonathan has staked his reputation on the the election, repeatedly promising it would be free and fair.
If current trends continue, he will avoid the need for an election run-off.
To win at the first round a candidate needs at least 25% of the vote in two-thirds of Nigeria's 36 states. The BBC reports official results are expected on Monday.
International monitors said Saturday's election could be Nigeria's first credible vote for decades. Previous polls were marred by widespread violence and vote-fixing.
Mr Jonathan was formerly the vice-president. He took over as president in 2010 when the incumbent died.