As evidence of vote rigging, Mr. Fayulu’s supporters pointed to two cities in the east, considered to be his stronghold, that were excluded from voting because of what the government said was instability and an Ebola crisis.

Officials deny the vote was rigged, and insist that it was the country’s best ever.

The Catholic Church, an influential and widely respected body that sent 40,000 election observers across the country, backed Mr. Fayulu’s claims to victory. Credible opinion polls before the vote had also shown him to be the winner. Suspicions over the results were reinforced after the Southern African Development Community, an intergovernmental regional bloc, called for a recount.

So, too, did the African Union, which last week expressed “serious doubts” about the vote count. But after a flurry of behind-the-scenes negotiations this week, most of the government’s critics backed down, and by Thursday were prepared to accept the outcome.

The African Union members “are undoubtedly all aligned on avoiding any potential flare-ups in violence in the D.R.C. to spread across their own borders,” said Adeline Van Houtte, an analyst at the Economist Intelligence Unit, using the initials for the Democratic Republic of Congo.

“So the question that remains is, ‘What caused the internal divisions that forced them to back down on the D.R.C. post-electoral crisis?’ ” A possible answer, she said, is that a lot of elections are planned in Africa in the coming year, including in South Africa.

With that in mind, she said, “some African leaders are probably wary of opening the door to every opposition leader to contest elections results that could lead to a recount.”