PORT-AU-PRINCE, HAITI, DEC. 17 -- The Rev. Jean-Bertrand Aristide, a messianic priest who harnessed the hopes of Haiti's miserable poor by preaching revolution, was hailed today as the runaway victor in Sunday's presidential elections.

His triumph ignited a daylong display of national euphoria unseen in Haiti since Jean-Claude "Baby Doc" Duvalier, the nation's self-proclaimed president for life, fled into exile nearly five years ago.

Although results were still being tallied, estimates based on poll samplings indicated Aristide, 37, had won in a landslide, collecting at least 60 percent and perhaps 70 percent of the vote and receiving three times as many votes as his nearest rival, foremer World Bank official Marc Bazin.

The vote was a unique expression of democratic will in a nation that has suffered under military tyrants and corrupt, murderous dictators -- none of them freely elected -- for most of its 186 years of independence. It was praised as "an incredibly successful election" by a White House delegation sent to observe the election.

"It's the first time in Haiti that the people have had a chance to express themselves democratically," said Turneb Delpe, a victorious senatorial candidate from Aristide's party. "This should be a lesson to the world about the will of the people."

Bazin demanded a recount of the vote in Haiti's Western District, the country's most populous region, saying the results there should be declared void, Reuter reported. But observers from the United Nations and the Organization of American States praised the vote despite what they described as irregularities, delays and confusion.

The White House team publicly hailed Aristide's victory as another triumph of democracy "like those in Managua, Berlin, Warsaw and elsewhere." But the winner is a radical leftist who is deeply resentful and distrustful of Washington, despite its persistent push for free elections in Haiti.

A number of prominent American politicians and statesmen visiting Haiti, in some cases for the first time, as election observers came away from meetings with Aristide with the impression that he was hostile to Washington, and they privately questioned his commitment to democracy. Some Western diplomats have expressed concerns about his economic program, which they consider incoherent.

But no one questioned his astounding popular support, which was abundantly evident in the capital today. Tens of thousands of people surged through the streets, singing the praises of "Titid," the nickname by which Aristide is known.

Gleeful, exuberant people in downtown Port-au-Prince danced to throbbing drum beats, pulsing through downtown, swirling around the gleaming white presidential palace and snaking up the city's steep asphalt alleys. Jogging in a hypnotic rhythm, they sang a Creole paean to the 5-foot-4 priest that sounded like a hymn:

"Oh, Titid! Oh, Titid! We were looking for you. We needed you. You are there and we are delivered. It's not for money, it's for dignity."

There was no looting. The army, which defied some grim predictions by safeguarding the campaign and Sunday's vote, looked on peacefully, riot gear ready but unneeded.

By the end of the day, there was just one confirmed case of violence A pregnant woman, Janine Desrosiers, 44, was shot and run over by police in a pickup truck who fired into a crowd of celebrating Aristide supporters, according to witnesses and news reports.

Throughout the capital, the smiling crowds carried leafy branches above their heads, symbols of an uprooting, liberty and drastic change. Drastic change is what Aristide -- a cleric, linguist and student of psychology -- has preached and promised for at least five years. And drastic change has a strong constituency in Haiti.

When Duvalier fled into exile Feb. 7, 1986, it ended the 29-year family reign begun by his father, Francois "Papa Doc" Duvalier, in fraudulent elections in 1957.

But his departure, while welcomed with an outburst of national exuberance similar to -- but more violent than -- today's, did not fundamentally shift power away from the Duvalierists -- a loose confederation of militiamen, bureaucrats, elites and local satraps.

Within a year or so of Jean-Claude Duvalier's flight, many Haitians had begun to wonder where their revolution went wrong. In the meantime, the Haitian army, a notoriously crooked and repressive force, held or controlled power through four governments in four years.

In March, the latest military ruler, Lt. Gen. Prosper Avril, fled the country, spurred by the threat of mob violence.

Aristide, who speaks English, Spanish, Italian, German, Hebrew and Portuguese as well as his native Creole and French, earned reknown in the mid-1980s for his fiery sermons at his Port-au-Prince church, St. Jean Bosco.

He was a leading member of the Ti Legliz, or Little Church, the Haitian coterie of liberation theologists who preached that the poor should organize to assert their dignity and to challenge the Duvalier regime and its notorious militia, the Tons-tons Macoutes. He took on the government, the white and mulatto elite and the U.S. Embassy.

He survived at least three assassination attempts, including one during Mass at his church in 1988 when gunmen burst in and sprayed the congregation and the pulpit with machine gun fire.

More than a dozen people were killed, the church was burned, but Aristide miraculously escaped. He became, for many of his stalwarts in the seamy slums of Port-au-Prince, a hero of mythic dimensions, the object of a cult of personality.

His order, the Salesians, expelled him in 1988 for using the pulpit to preach class warfare. He remained a priest, but was unable to celebrate Mass in public. Recently, he has said he is willing to leave the priesthood if necessary.

Special correspondent J.P. Slavin in Port-au-Prince contributed to this report.