Conde’s challengers have said the October 11 election was tainted by widespread fraud and mismanagement and have urged supporters to take to the streets, raising the spectre of unrest in the days to come.
The poor west African state has a history of post-election violence, prompting the international community to call on all parties to pursue their grievances through the courts rather than protests.
Conde’s main rival Cellou Dalein Diallo dismissed the result as an “electoral farce”, telling AFP “we cannot recognise such a victory”.
Results published by the Independent National Electoral Commission from areas representing over 90% of Guinea’s voters showed Conde winning an outright majority with nearly 2.2 million ballots.
Turnout was put at around 66% of the six million voters, well below an initial estimate of 75%.
One suburb of the capital Conakry and the overseas votes cast by Guineans living in New York have yet to be counted.
Conde’s seven challengers have said the vote, only the second democratic presidential poll since Guinea gained independence from France in 1958, was marred by vote-rigging and demanded a re-run.
Conde, 77, had gone into the campaign promising to deliver a “KO blow” to his opponents by winning victory at the first round, avoiding a run-off against his closest rival.
Guinea’s first ever democratic election in 2010 went to a second round between Conde and former prime minister Diallo, which Conde narrowly won.
While Diallo grudgingly conceded defeat in that election he refused to recognise the result of Sunday’s rematch – in which he garnered more than 1.06 million votes, according to the latest results.
“When the president [of the electoral commission] decides that anyone holding an electoral card can vote, even without an envelope in violation of the electoral code, it shows the illegal way in which the election has taken place,” Diallo said.
“We reserve the right to use all legal means necessary, including peaceful protest,” he said.
The 63-year-old and the six other opposition candidates all demanded a re-run and warned a proclamation of victory by Conde at the first round would vindicate their suspicions of vote-rigging.
Diallo had dubbed the vote “a masquerade, a massive fraud” and called for protests when he pulled out of the race on Wednesday.
The election has caused increased tensions, with around a dozen people killed in clashes between Conde and Diallo supporters ahead of polling day.
An EU election observer team criticised the electoral commission for poor organisation and a “lack of preparation”.
Conde, who spent nearly three decades in exile in France, led the opposition to Guinea’s dictatorial first president after independence from France, Ahmed Sekou Toure.
He says the achievements of his presidency include an overhaul of the army and judiciary, the completion of a hydroelectric dam and reforms to make mining contracts more transparent.
Despite being rich in bauxite, the ore used to produce aluminium, the country is one of the world’s poorest and was blindsided by a severe outbreak of Ebola, which began in the country’s southern forests in December 2013 and then spread to neighbouring countries.
Half the population lives below the UN poverty line, and according to the World Bank, per capita income in 2014 was just $470 with many lacking access to electricity or running water.