Presidential candidate Salvador Jorge Blanco claimed victory late tonight for his Dominican Revolutionary Party in what appeared to be the island nation's first peaceful and undisturbed election since independence.

"We are the winners," Jorge Blanco, 55, told a press conference at his home. "We proclaim it with a very comfortable majority." Party officials said unofficial results from selected precincts showed them with 48.8 percent of the vote, well ahead of former president Joaquin Balaguer with 33.8 percent. Another former president, Juan Bosch, was running a distant third with 10 percent of the tally, the party's figures said.

Voting was extended two hours after the scheduled closing time in order to accommodate thousands of people who braved torrential rains in western rural areas and slow-moving lines to flock to the polls. Some projections said as many as 2 million people had turned out, or 40 percent of the entire population.

Police said there were only scattered, minor incidents of violence, making this the first election that so far has not been subject either to military or U.S. intervention. But they were called to aid a police van that had tried to remove a voting box at 6 p.m., apparently unaware that the vote had been extended. The van had been surrounded by angry voters who slashed its tires.

Police also briefly surrounded the offices of the newspaper El Dia to halt its attempted publication of an extra edition against earlier general election news censorship orders.

A Revolutionary Party victory would affirm both the current government led by President Antonio Guzman and Jorge Blanco's social democratic platform of heavy state investment to cure the country's serious unemployment problem. Guzman decided not to seek reelection.

The Reformist Party, which claimed earlier that it was sure of winning, was already charging that the Revolutionary Party government had committed fraud, opening some polling places up to five hours late and then slowing procedures so late arrivals could not vote.

"The polls before the election were paid off and the newspapers, too," said Guarionex Lluberes Montaz, the Reformist candidate for mayor of Santo Domingo, explaining why few analysts expected a Reformist win. "We will take the countryside even bigger than the city," he predicted.

At stake in the election was the entire government of the island's 5.5 million population, from president through town councils. It also was a kind of referendum on style, the last hurrah of two former presidents of the old strongman tradition: Balaguer on the right and Bosch, president for seven months in 1973, on the left.

Opposing those bitter rivals, both in their seventies and given to rambling speeches full of poetry and reminiscence, was the slick, modern and computerized media campaign of Jorge Blanco and the Revolutionary Party, which calls itself the new generation.

But voters could choose among 20 parties altogether, and at several crowded polling places they stood in orderly lines for up to four hours to do it, taking the sheaf of 20 different colored papers into the voting booths and emerging with one or two stuffed inside a sealed envelope.

In the working-class suburb of Ensancha las Americas, east of the capital, Ana Josefa Valdez, 54, pushed through the crowds outside a tiny high school office after voting there for Jorge Blanco.

"He's a real man. I'm hopeful that he'll bring more work to the country, and to my sons," she said.

American pollster Mark J. Penn, of Penn and Schoen Associates of New York, said his surveys since October for Jorge Blanco have shown the Revolutionary Party to be strongest in the cities among the working and middle classes. The western rural areas near the Haitian border were considered Balaguer strongholds, while inner-city slums and the eastern industrial area of La Romana, run by the Gulf & Western Co., were thought likely to support either the legal communist parties or Juan Bosch and his Dominican Liberation Party.

The Dominican armed forces, which in the past have either taken power themselves or intervened in elections to back their civilian choices, stood quietly outside today.

"We were told to stand well back from the polling places," said a young Navy officer assigned to the coastal fishing village of Yuayacanas about 45 miles east here. He refused with a grin to talk politics.

"You know you shouldn't ask me about that," he said. "All the chiefs have agreed this time: let whoever wins be the winner."