with the leading candidate hovering right at the 50 percent mark needed to avoid a run-off with his top challenger.
As the last third of votes came in, the percentage held by Deputy Prime Minister Uhuru Kenyatta flipped and flopped over the 50 percent mark. His opponent, Prime Minister Raila Odinga, needed a strong performance in the remaining ballots to force a second round run-off.
Eight candidates ran for presidents, so if any of the bottom six candidates captures a significant portion of the outstanding ballots, that could also push Kenyatta below 50 percent.

A Kenyatta win could have far-reaching consequences with Western relations. The son of Kenya's founding father, Kenyatta faces charges at the International Criminal Court for his role in directing some of the vicious postelection violence that followed Kenya's 2007 presidential vote, when tribe-on-tribe attacks killed more than 1,000 people.
The U.S. has warned of "consequences" if Kenyatta is to win, as have several European countries. Britain, which ruled Kenya up until the early 1960s, has said they would only have essential contact with a President Kenyatta.
The U.S. Embassy in Kenya is larger than any American mission in Africa, underscoring Kenya's strong role in U.S. foreign policy. The U.S. also has military forces stationed here near the border with Somalia. Kenya, the lynchpin of East Africa's economy, plays a vital security role in the fight against Somali militants.
Kenyatta's ICC trial is set to begin in July and could take years, meaning that if he wins he may have to rule Kenya from The Hague for the first half of his presidency. Another option is, as president, to decide not to go. But that decision would have even more damaging effects for Kenya's standing with the West, and Kenyatta has promised he will go even if he wins.
Whether or not Kenyatta finishes with over half of the votes, most observers expected legal challenges to be launched after a myriad of failures in the systems Kenya's electoral commission set up.
The first problems were evident right as the voting began early Monday. An electronic voter ID system intended to prevent fraud failed across the country for lack of electricity in some cases and overheating computers in others. Vote officials instead used manual voter rolls.
After the polls closed, results were to be sent electronically to Nairobi, where officials would quickly tabulate a preliminary vote count in order to maximize transparency after rigging accusations following the 2007 vote. But that system failed too. Election officials have indicated that computer servers overloaded but have yet to fully explain the problem.
On Tuesday, as the early count system was still being used, election results showed more than 330,000 rejected ballots, an unusually high number. But after the count resumed with the arrival in Nairobi of manual tallies, the number of rejected ballots had dropped to almost nothing, and the election commission on Thursday gave the head-scratching explanation that the computer was mistakenly multiplying the number of rejected ballots by a factor of eight.
Odinga's camp on Thursday said some votes had been doctored and called for a halt to the tallying process. It said the tallying process "lacked integrity." A day earlier, Kenyatta's camp accused the British high commissioner of meddling in the election and asked aloud why there were an unusually high number of British troops in the country.
The election commission said it expected to have final results by the end of Friday, though observers said it was still possible the count would go into the weekend.
There were fears going into the election that the violence that rocked Kenya five years ago would return. A separatist group on the coast launched attacks on Monday that ended in the deaths of 19 people, but the vote and its aftermath has otherwise been largely peaceful.
However, it's the announcement of results that could stir protests, especially if the supporters of either Odinga or Kenyatta feel robbed. Diplomats say that the public reaction to an election loss by the losing candidate will set the tone for whether violence breaks out.
The political battle between the families of Kenyatta and Odinga goes back to the 1960s and to the two candidates' fathers. Jomo Kenyatta was Kenya's first president after the end of British colonial rule. Jaramogi Oginga Odinga served as the country's first vice president then. The two later had a falling out.
If a runoff is declared, it would be most likely held in late April, depending on how long legal challeng