Caracas: Youthful state governor Henrique Capriles won Venezuela's first-ever opposition presidential primary on Monday by a wide margin, emerging as the single candidate who will try to end President Hugo Chavez's 13 years in power.

Capriles, the 39-year-old governor of Miranda state, faces a tough task in ousting Chavez, a charismatic campaigner with a loyal following and the full powers of the state to back his candidacy in October 7 elections.

Opposition election chief Teresa Albanes announced the preliminary results, saying that Capriles won about 62 percent of the vote, beating Zulia state Gov. Pablo Perez by a margin of more than 30 percentage points.

Chavez's opponents lined up to vote in many areas, surpassing most expectations with a turnout of about 2.9 million ballots cast out of Venezuela's 18 million registered voters.

Capriles had been the front-runner in pre-election polls among five contenders, presenting a younger, energetic alternative to the 57-year-old Chavez, who has recently battled cancer.

"He's going to be the candidate who can get us out of this giant hole we're stuck in," said Carmen Gloria Padilla, a 66-year-old telephone company employee who voted for him. Thousands of supporters celebrated the win outside Capriles' campaign headquarters, some holding small flags bearing the slogan "There is a way." Fireworks exploded in the sky above the crowd.

"I aim to be the president of all Venezuelans," Capriles shouted, wearing a baseball cap emblazoned with the yellow, blue and red of Venezuela's flag.