ABIDJAN, Ivory Coast (AP) _ Opposition supporters accused the ruling party of cheating in this country's first multiparty vote Sunday, and they smashed ballot boxes they said were stuffed beforehand.

The vote marked the first time a leader of one of Africa's one-party states was challenged at the polls since a wave of pro-democracy protests began sweeping sub-Saharan Africa early this year.

Preliminary results from two of the 163 administrative regions gave more than 90 percent of the vote to octogenarian President Felix Houphouet-Boigny, who has ruled Ivory Coast since independence from France in 1960.

The sole challenger, history professor Laurent Gbagbo, showed reporters stacks of ballots marked for Houphouet-Boigny. Gbagbo charged the ballots had come from one of dozens of boxes being stuffed with votes to rig the election.

''We cannot ask them to re-do the elections, because these are not elections,'' said Gbagbo, who had been mobbed at pre-election rallies by youthful supporters who hail him as their liberator.

He added, ''They are stuffing boxes in suburbs and in towns where (Gbagbo's coalition) is well-entrenched. This is criminal. It is cheating, treachery, to steal the election.''

Gbagbo said that of the 1,500 ballots in the box, which was seized a half- hour after voting began, only seven were marked for his coalition.

At one polling station, voters said the opposition party representative arrived 90 minutes late, and voting had already begun. The opposition representative demanded to see the ballot boxes. After being refused, his supporters smashed open a box.

Suspicious boxes were smashed at other polling stations as well, Gbagbo's supporters said. Gbagbo said the government had also set up phantom polling booths where no one voted but the ballots were all marked for the president.

Interior Minister Leon Konan Koffi said the fraud charges were lies. Gbagbo's supporters destroyed ballot boxes to stop elections they knew they would lose, he said.

Gbagbo, who decided to run against the advice of other politicians who argued the elections would be fraudulent, said it had been worthwhile to at least campaign.

''Nobody ever thought we would get multiparty democracy while Houphouet- Boigny was in Ivory Coast,'' he told reporters. ''It was time to put a stop to the system of there being just a single candidate.''

Middle-class Ivorians and the urban poor appeared allied with the socialist-minded Gbagbo, while peasants rallied around Houphouet-Boigny.

A major issue was the government's insistence that African foreigners be allowed to vote, as they have in past elections. Such Africans comprise at least a third of the population of 10 million. Most support the president out of gratitude for allowing them to stay, or fear the opposition might send them packing because of the country's economic problems.

Among the most powerful weapons in the ruling party's arsenal are a nationwide network built up during more than 30 years of single-party rule, funds from compulsory contributions exacted from civil servants' salaries, and the worship by some of Houphouet-Boigny.

''Houphouet saved us from the cruel forced labor of the French, and for that he will get my vote until he is buried,'' said N'dri Kouassi, a retired farm laborer in his 80s.

Villagers have been untouched by the weeks of rioting led by university students and joined by dissatisfied urban workers.

The rioting earlier this year forced Houphouet-Boigny to legalize political opposition, which had been banned since he took power.

Opposition politicians like Gbagbo say democracy will help solve the continent's economic crisis brought on by mismanagement, corruption and slumping world prices for raw materials, cocoa and coffee.

Gbagbo also said the personality cult around Houphouet-Boigny blocks the country from developing.

The opposition has promised compulsory education, improved health services, and a younger, motivated leadership. It is handicapped by a voting age of 21 years, which excludes thousands of student supporters.

Gbagbo, a political detainee from 1971 to 1973, says the president has run Ivory Coast like a personal fiefdom and enriched himself and his cronies from state coffers.

African governments are watching: Ivory Coast is one of the most stable nations on a continent where governments change more often because of coups and wars than elections. Houphouet-Boigny's conservative policies brought about what Western backers called ''an economic miracle'' in Africa.

Houphouet-Boigny has made it difficult for the opposition. He refused to publish a voters' roll until the day before the elections, and denied the opposition access to state radio and television until the 10-day campaign began Oct. 18.

Houphouet-Boigny's picture dominated many broadcasts. His party ran footage of the president in younger days kissing babies, harvesting sugar cane, and meeting world leaders.