NAIROBI — The chief justice of Kenya’s Supreme Court, David Maraga, is a Seventh-day Adventist who refuses to preside over a court case on a Saturday. Once accused of corruption, he went on live television and swore on the Bible that he had never taken a bribe.

Now Maraga has become a household name almost overnight, with many calling him Kenya’s national hero. Some even want to rename a street in Nairobi, the capital, with his name.

On Friday his court invalidated last month’s reelection of President Uhuru Kenyatta, saying the vote had been tainted by “irregularities and illegalities’’ and sending the country back to the polls.

The decision has become an unlikely unifying force for a country that had been deeply polarized in the weeks before and after the election. Much of the division had been stoked by the candidates, Kenyatta and his opponent, Raila Odinga, who were accused of stirring ethnic tensions for electoral gains.

Kenyatta promised Saturday to ‘‘fix’’ the judicial system a day after the court’s ruling, and he warned the chief justice and judiciary not to interfere with the electoral commission as the country prepares for a new vote, the Associated Press reported.

Kenyatta again accused the court of overturning the will of the people after he had been declared the winner of the Aug. 8 election. The judiciary has a ‘‘problem,’’ he said in comments to officials from county assemblies.

‘‘We shall show you in 60 days that the will of the people cannot be overturned,’’ Kenyatta said. ‘‘We will come back and revisit this issue.’’

In Kenya, where courts have a long history of corruption and are often viewed as an extension of the government, the election ruling was stunning. It shocked even Kenyatta, who was so confident that the court would side with him that he had urged Odinga to resolve the dispute by legal means and not in the streets.

Trust in the justice system has been so low that before the ruling, Odinga said he had little hope that the court would make a fair decision. His petition to overturn the vote, he said, was more an opportunity to publicize the opposition’s arguments that the election was a fraud.

But four of the court’s six justices voted to order a new election within 60 days.

The ruling was the first of its kind in Africa and a powerful reminder for democracies elsewhere of the importance of independent institutions. Kenyans celebrated what they saw as a victory for the country’s institutions, with many saying they were more interested in a clean and transparent process than in seeing their candidate win.

Maraga blamed the electoral commission for irregularities and absolved Kenyatta of any misconduct, a decision that many Kenyans said was driven by the desire to prevent the kind of violence and ethnic clashes that erupted over elections in 2007 and 2013.