LIMA, PERU, JUNE 10 -- Alberto Fujimori, a soft-spoken agricultural engineer who has capitalized on widespread public distrust of traditional politicians, won today's presidential runoff over novelist Mario Vargas Llosa.

Three respected polling companies that conducted exit polls and examined selected unofficial results each gave Fujimori a margin of at least 10 percentage points. The actual vote count was slow to begin and will not be completed until the end of the month, but Vargas Llosa quickly accepted the survey results as valid.

"I accept the decision of the Peruvian people," Vargas Llosa told about a thousand supporters outside his headquarters. "I congratulate Alberto Fujimori on his victory and . . . wish him success in the difficult responsibility that the people have given him. . . . Now it is necessary to heal the wounds."

The apparent margin of victory came as a surprise, as recent preelection polls had called the race a dead heat. Surveys of voters leaving the polls showed a clear split: The poor chose Fujimori while the well-heeled backed Vargas Llosa.

Fujimori, the son of Japanese immigrants, made a stunning rise from obscurity in three months. At the beginning of March he barely figured in the polls. But in the April 8 first-round vote he finished a close second, emerging as a viable alternative to Vargas Llosa, 54, and the stringent economic adjustment he advocated as a remedy for Peru's many woes.

"We Peruvians must look forward, because the crisis in its various forms is battering us horribly," Fujimori said in a press conference, describing himself as the "probable next president of Peru."

Fujimori was accompanied by his two vice presidential running mates -- Maximo San Roman, owner of a small factory, and Carlos Garcia, a Baptist minister. None of the three had been politically prominent.

Fujimori was sharply criticized during the campaign for the vagueness of his proposals. Saying his Change 90 movement was independent and centrist, he never fully described its plan to restart the moribund Peruvian economy without the painful sacrifices that Vargas Llosa said must be undertaken.

But Fujimori apparently benefited heavily from votes that in the first round had gone to several leftist parties and to the ruling APRA party. Learning of the projected election result, political analyst Cesar Hildebrandt, a supporter of Vargas Llosa, complained bitterly that "losing forces" had joined together to thwart reform.

The projected result would be an angry rejection of Peru's traditional ruling class -- a small, well-to-do, overwhelmingly white elite centered in Lima.

Fujimori positioned himself as the candidate of the poor, brown-skinned majority. He campaigned heavily in bleak shantytowns and fetid slums, criticizing the "little white ones" and asking Peruvians to vote for "a president like you."

He attacked Vargas Llosa for his links with such veteran conservative politicians as former president Fernando Belaunde Terry and former Lima mayor Luis Bedoya. Many voters apparently saw as an asset the fact that Fujimori, a former president of the National Agrarian University, had no political past.

"Vargas Llosa is a good man, but the people around him are the same old politicians," said Raimundo Llacuachaqui, who was waiting his turn to vote outside a school in the working-class Lima neighborhood of Lince. "Perhaps if he had been alone I could support him. But Fujimori's movement has different people, new faces."

Fujimori also was boosted by his Japanese ancestry. Japan is a much-admired country here, and a number of voters said they considered the Japanese to be honest and hard-working. Fujimori posed for campaign photographs in karate garb and claimed several times that he could attract additional foreign aid from Japan, prompting a denial from Tokyo of any promised new aid.

The two candidates were competing to succeed President Alan Garcia, who was seen as one of Latin America's brightest young leaders when he took office in 1985 but now is blamed for helping lead Peru into an unprecedented crisis.

Inflation, unemployment, political violence and general misery have all soared dramatically in five years.

Garcia adopted a confrontational attitude toward Peru's creditors, limiting payment on the nation's $17 billion foreign debt. The economy enjoyed two years of rapid growth, then collapsed. Per-capita gross national product fell by nearly one-fourth in 1988 and 1989, and real incomes plummeted.

Fujimori has promised to halt inflation without imposing a sharp belt-tightening adjustment that could deepen the recession. The country's reserves are exhausted, as is its credit with international lenders. The Maoist Shining Path guerrillas have more and more of the country under siege.

Change 90 lacks a majority in the Congress elected April 8. To legislate a program, Fujimori would need to join forces either with APRA and the left or with Vargas Llosa's conservative Fredemo coalition. But Fujimori promised to maintain independence if elected.

Voting went largely without incident in metropolitan Lima, home to a third of Peru's 21 million people. But there was conflict in highland regions, where the Shining Path attempted to disrupt the election. A bomb killed one man in Huancayo, where Shining Path had called an "armed strike" and ordered people to remain in their homes.

Despite claims by political leaders that the first-round vote in April represented a victory over Shining Path, absenteeism reached record highs in areas where the guerrillas are strong, despite the fact that Peruvians are compelled by law to go to the polls.

It was not yet known how many people had failed to vote in today's runoff, although exit polls indicated that up to 10 percent may have deposited null ballots.