A calculation of ballots in 33 of Nigeria's 36 states and the federal capital Abuja showed Bola Tinubu of the governing party closing in on victory in the country's disputed presidential election.
Tinubu's possible win strengthens the All Progressives Congress (APC) hold on power in Africa's largest oil producer and most populous country, albeit he inherits a slew of issues from departing President Muhammadu Buhari.
Nigeria is grappling with Islamic insurgencies in the northeast, armed attacks, killings, and kidnappings, the conflict between livestock herders and farmers, cash, petrol, and power shortages, and persistent corruption, which opponents claim Buhari's party has failed to eradicate despite pledges.
With just four states remaining to declare, Tinubu was ahead with around 34% or 7.6 million legitimate ballots counted, making it extremely probable that he will be proclaimed the victor of the weekend election on Tuesday.
Opposition parties, however, denounced the results as the outcome of a faulty process that saw several technical issues due to the deployment of new technology by the Independent National Election Commission (INEC), and called on its chairman, Mahmood Yakubu, to quit.
Tinubu invited supporters to vote for him based on his track record as Lagos state governor at the turn of the century, during which he reduced violent crime, improved the city's horrendous traffic, and cleaned up trash.
The 70-year-old has, however, sometimes appeared frail in public, slurring his speech and answering questions with platitudes, leaving some to doubt how effective he would be.
At 29% of the vote, or about 6.4 million valid ballots, Atiku Abubakar of the main opposition People's Democratic Party (PDP) was lagging. Peter Obi of the smaller Labour Party received 25% of the vote or around 5.5 million votes.
Obi's candidature drew young people and urban, better-educated voters who were tired of corrupt politics in the past.
The results were disputed by both parties, as well as the minor opposition ADC.
The results being declared at the National Collation centre have been heavily doctored and manipulated and do not reflect the wishes of Nigerians expressed at the polls, they said in a joint statement.