NAIROBI - The wealthy son of Kenya's independence hero and now president-elect, Uhuru Kenyatta brushed off international charges of crimes against humanity to present himself as a statesman with the economic skills to help ordinary Kenyans.

Backed by voters from Kenya's biggest tribe, the Kikuyu, in a nation where ethnic loyalties tend to trump ideology at the ballot box, the 51-year-old who is listed as Kenya's richest man won a presidential election by a tiny margin.

Kenyatta - hailed as "njamba", or warrior, by his supporters - fought a slick and well-funded campaign to edge above the 50 percent-mark needed to win outright by about 8,400 votes out of more than 12.3 million cast.

But battling for the post his father held after Kenya's independence from the British in 1963 may have been the easy part and the U.S.-educated Kenyatta's biggest challenges may emerge once in office.

Moving into State House, the president's residence that is a short walk from his home in Nairobi, may not be straightforward as his win has been challenged by his main rival, Prime Minister Raila Odinga, possibly leading to legal suits.

Even before the vote, Kenya's Western donors indicated a Kenyatta presidency would complicate diplomatic ties because he and his running mate, William Ruto, are both charged by the International Criminal Court (ICC) over their alleged role in the tribal blood-letting after the last election in 2007.

Unperturbed, Kenyatta told a rally two days before the election: "There are those who said that Uhuru and Ruto will not run because we are facing cases in Europe, but God has opened that road for us so that people can decide."

Closer to home, Kenyatta will have to hold together a coalition with Ruto who hails from the Kalenjin tribe, long at odds with Kenyatta's Kikuyu over one of Kenya's most contentious issues - land ownership.

It is a sensitive issue for Kenyatta himself. Challenged in a presidential debate on how much land he and his family controlled, Kenyatta avoided a direct answer but did mention 30,000 acres on the coast. That was enough to trigger fevered critical debate on Twitter. Critics say he owns far more.

"COLONIAL" MEDDLING

He has also already had to shake off jibes from his rival Odinga that he would have to govern by Skype from the ICC's headquarters in The Hague if elected.

"I will be able to handle the issue of clearing our names ... while at the same time ensuring that the business of government continues," he promised on the campaign trail.

However, the case may have played to Kenyatta's advantage when the governments of the United States, Britain and other Western nations said Kenyans should be wise in choosing their leader.

That allowed his supporters to present such comments as "colonial" or "imperialist" meddling, burnishing Kenyatta's nationalist credentials in the former British colony.

"It has basically been turned into an instrument of mobilisation for votes," said Godwin Murunga, deputy director at the African Leadership Centre in Nairobi.

Kenyatta, bearer of Kenya's most famous name and ranked by Forbes magazine as its wealthiest man, promised to tackle "real issues" affecting ordinary Kenyans such as housing shortages and unemployment.

Heir to his late father's vast business empire, spanning land estates, the country's biggest dairy company and five-star hotels, as well as interests in banking, insurance and exclusive schools, he can count on the support of many of Kenya's business elite, dominated by Indians and Kikuyus.

LOOMING TENSIONS

Nevertheless, his supporters say their candidate remains a "man of the people" with an easy-going, popular touch.

The graduate of Amherst College in Massachusetts has pointed to his experience as finance minister to show off his economic stewardship and readiness to rein in excess.

In office, he suggested ministers and high-ranking officials downgrade their vehicles, which plays well in a nation with a huge gap between rich and poor.

"My record at the Ministry of Finance is there. When it comes to the issue of transparency and openness in government which is one of the key pillars in our manifesto, my record speaks for itself," said Kenyatta, striking the defiantly defensive tone that has been a keynote of his campaign.

He mooted the idea that parliamentarians - some of the best paid in the world - should pay tax. But he has also been criticised for not doing enough to improve basic services in his own rural parliamentary constituency.

Tensions in his government could emerge in office. His election alliance has been dubbed a "marriage of convenience" that was formed to let Kenyatta and Ruto show a united front to the ICC, but it may not have deep support beyond the vote.

Kenyatta's Kikuyu and Ruto's Kalenjin have long been tribal rivals and in the 2007 vote the two men backed different candidates. The ICC has accused the two of sending their tribal loyalists out to attack each others' supporters after that poll.

"The political architecture at the top is rather convenient and limited to those cobbling together that alliance," said Murunga. "But it is not translating on the ground and, for me, that would be a huge flashpoint to think about."

Although he has promised to cooperate with the ICC, Murunga questioned whether Kenyatta's resolve will hold in office.

"The presidency is a useful incentive not to follow the ICC process," he said. "It is a very, very tempting incentive."

Reuters