The son of Azerbaijan's ailing president won an overwhelming victory in elections to choose his father's successor. But western observers and the opposition alleged massive voting irregularities. One observer said there were so many problems with Wednesday's election - among them ballot-box stuffing and unmonitored voting - that he stopped trying to record them all. Violence flared during the vote, with police clashing with protesters twice during an hours-long standoff in the capital, Baku. With more than two-thirds of Azerbaijan's 5,111 districts reporting, President Geidar Aliev's son, Ilham Aliev, had nearly 80 percent of the votes, according to preliminary results posted by the Central Election Commission. His closest rival, Isa Gambar, had about 11 percent. As the count progressed, Aliev cleared a majority of the votes cast, meaning there would be no runoff with any of the other seven candidates, the commission said. Aliev stood for the ruling Yeni Azerbaijan party after his father - hospitalized in the United States - pulled out of the race less than two weeks ago. More than 71 percent of the former Soviet republic's 4.4 million electorate voted, election commission chairman Mazahir Panahov said. Gambar, leader of the opposition party Musavat, or Equality, claimed that he won a majority, charging that there were irregularities that favored Aliev. Many in Baku complained that they were prevented from registering and that others cast multiple votes. Inside his party headquarters, Gambar waved a stack of ballots marked for Aliev that he claimed had been filled out before the election, and claimed he soundly beat the president's son in districts monitored by international observers. "This is the beginning," protester Majif Mammedalizade, 37, said of the demonstration. When voters wake up Thursday and "everyone knows the vote is false, Ilham Aliev has no chance," he said. One OSCE observer, Ivan Lozowy, said he eventually stopped recording irregularities because he saw so many at the 35 polling places he visited Wednesday. He said violations included multiple voting, falsified ballots, and ballot counting in absence of observers. A melee broke out after several hundred opposition supporters gathered outside Musavat headquarters after polls closed, chanting Gambar's name and applauding as he arrived. Police in riot gear surrounded the crowd and later closed off the street to prevent others from joining. A group of demonstrators charged through the police line, prompting police to try to beat back the crowd back with truncheons. Protesters wielding sticks drove police back again, but police reinforcements with metal shields then pushed them back toward the party headquarters. Yashar Aliyev, deputy chief of the Baku police, said 15 Musavat activists were detained. The commanding police officer at the scene, whose orders to the crowd to disband were ignored, said there were injuries on both sides, and some protesters and police were bloodied or bandaged. Peter Eicher, the head of the Organization for Security and Cooperation in Europe's observer mission, urged the police commander to use restraint, saying the protesters were being peaceful. "We're trying to avoid bloodshed," he said. The officer said that "if they don't move we'll attack them." Shortly afterward, police charged the protesters again, beating some with truncheons, tossing bricks, and dragging away at least half a dozen, going around a line of OSCE observers trying to prevent violence. A police official said 10 people were detained in the second clash and that 20 police suffered moderate to serious injuries in the unrest. Even before election day, international organizations reported widespread irregularities, including biased media coverage, violence against opposition protesters ignited by police or pro-government provocateurs, and intimidation of opposition sympathizers. Ilham Aliev has threatened decisive action against anyone who resorts to violence over the election results. Geidar Aliev, 80, has not been seen in public since he was hospitalized in Turkey on July 8, and is now being treated in the United States. A longtime leader of Azerbaijan's Soviet-era Communist Party, he returned to power in 1993 following a military coup. He is regarded by many as a figure of stability and was widely expected to win before he withdrew. Ilham Aliev, 41, hoped to inherit the allegiance of his father's supporters and has pledged to continue his policies. "I know there is a person who takes care of us," said Esmiralda Yeganova, 28, who voted for Aliev. "If another person is in power there will be big changes and I don't want changes. I want calm, stability." **PHOTO CAPTION*** Opposition supporters clash with the police outside the Musavat party headquarters in Baku, Azerbaijan, late Wednesday, Oct. 15, 2003, with portraits of the party leader Isa Gambar on the wall. (AP Photo/Efrem Lukatsky)