At 08:42GMT Agence France-Prresse reported that Kenya presidential candidate William Ruto scored 51.25 percent of the vote, reversing earlier gains for Raila Odinga, who had 48.09 percent, according to figures from the Independent Electoral and Boundaries Commission (IEBC), which has tallied results from nearly 50 percent of constituencies.
Odinga is a veteran opposition leader now backed by the ruling party, while Ruto, who was widely expected to succeed President Uhuru Kenyatta, saw his boss Uhuru Kenyatta joining hands with former foe Odinga in a dramatic shift of political allegiances.
Riot police were deployed overnight inside the commission's heavily-guarded tallying centre in the Kenyan capital Nairobi after political party agents disrupted the process, hurling rigging allegations at each other.
The commission's chairman Wafula Chebukati on Friday accused party agents of delaying the tallying process by haranguing election workers with unnecessary questions.
The wait has left Kenyans weary, with many hoping that any disputes over the result are addressed peacefully through legal means.
Authorities in the East African nation have been struggling to get the economy back on its feet, after the twin shocks of the Covid-19 pandemic and the war in Ukraine, which sent food and fuel costs spiralling.
The economy has been a key theme throughout the campaign, with many citizens calling on leaders to tackle the cost-of-living crisis.
Turnout was about 65 percent, much lower than the 78 percent recorded in 2017, a reflection, some observers say, of the disenchantment with the political elite, particularly among young people.
The winner of the presidential race needs to secure 50 percent plus one vote and at least a quarter of the votes in 24 of Kenya's 47 counties.
If not, the country will be forced to hold a runoff within 30 days of the original vote.
Both frontrunners have pledged to ensure calm after the outcome is known, with Kenyans still haunted by the deadly violence that followed the 2017 and 2007 polls.
The election is being closely watched by an international community that views Kenya as a pillar of stability in a volatile region, with US Secretary of State Antony Blinken describing the country's polls "as a model for the continent".
"We encourage peace and patience as the vote tallying continues from the August 9 elections," Blinken said on Twitter late Saturday.
