"Subject to the validation of results by the supreme court, the two candidates who have obtained the most votes go forward into the second round," Ben Sekou Sylla, president of the CENI, told reporters on Friday.
Defeated candidates have eight days to challenge the results in the supreme court, which then has three days to make a ruling.
The poll has been billed as the best chance for the West African state, the world's number one exporter of aluminium ore bauxite, to emerge from half a century of dictatorship.
Lydie Boka, a political risk consultant, said the final round of voting will be close, and has the potential to lead to a power sharing deal, as has been seen in Kenya and Zimbabwe.
Under this situation, third place Toure could be the kingmaker, Boka said.
A succession of military and authoritarian leaders have controlled the country of 10 million since it won independence from France in 1958.
Results had been due on Wednesday but Guinea's supreme court gave election organisers an extra 48 hours to publish results because of "difficulties concerning logistics, transport and security".
Almost 4,000 local and foreign observers had been deployed for the election and have said that the vote went as well as it could have, considering the poor state of infrastructure and a lack of democratic tradition.
A number of candidates including Diallo and Conde, however, have alledged fraud and ballot stuffingoccured during the vote.
If successful, the election is likely to attract new investment and lead to an increase in foreign aid.
Said Djinnit, the United Nations special representative for West Africa, has urged "all candidates and their supporters to show restraint and civility in order to preserve the atomosphere of calm and serenity".