Caracas, Venezuela -- Venezuelan President Hugo Chavez has secured six more years in office after defeating his opponent in a closely watched presidential election that both candidates described as a historic vote.

Chavez, who has been president since 1999, overcame an energetic challenge from opposition candidate Henrique Capriles Radonski, according to results released late Sunday.

Fireworks peppered the sky over Caracas after the provisional results were announced.

"Today we have demonstrated -- comrades, compatriots -- that our democracy is one of the best in the world," Chavez said in a speech from the balcony of the presidential palace to thousands of supporters who cheered and waved flags.

He thanked those who had voted for him and acknowledged those who had voted against him, applauding their "democratic attitude."

With 90% of the ballots counted, Chavez had more than 54% of votes, with nearly 45% for Capriles, Venezuela's National Electoral Council said Sunday night.

Chavez had secured 7.4 million votes and Capriles 6.1 million votes, election officials said. It was a significant showing -- but not enough to win -- for Capriles' campaign, which had criticized the Chavez administration for inefficiencies, infrastructure shortcomings and corruption.

"We began the construction of a path," the opposition coalition candidate told supporters after conceding his defeat.

Capriles congratulated Chavez on his victory and urged him to take into account the different views expressed by voters.

"Being a good president means working for the vision of all Venezuelans," he said.

Chavez has had more than a decade to implement his vision of 21st century socialism, a view that emphasizes the use of state oil windfalls to fund social programs.

During his campaign, he highlighted his accomplishments in housing, education and health initiatives and acknowledged he needed to do more on crime and government bureaucracy.

The ebullient leader is 58 years old and has been visibly weakened by two surgeries for cancer. He has kept secret the kind of cancer he has and his prognosis.

His victory gives him "the opportunity to consolidate his policies" and also reaffirms the approach his government has taken to international relations, said Miguel Tinker Salas, a Latin American history professor at Pomona College in California.

Chavez's influence over Latin America's left-leaning governments has often rankled the United States, Venezuela's largest trading partner. Venezuela is the fourth-largest exporter of oil to the United States.

Despite that tight economic relationship, the two countries are far from close allies: Chavez often rails against the United States and its allies as "imperialists" and has supported controversial world leaders like President Mahmoud Ahmadinejad of Iran.

The election result Sunday means the U.S. government will have to continue to deal with Chavez's provocatively independent brand of diplomacy.

"I think Washington will have to start getting used to the fact that countries in Latin America, especially South America, are charting their own course," said Tinker Salas.

Observers had said Capriles, 40, represented a moderate alternative to Chavez, the charismatic standard-bearer of the Latin American left.