Mexico City ? The ruling party’s Felipe Calderon won the official count in Mexico’s disputed presidential race Thursday, a come-from-behind victory for the stiff technocrat. But his leftist rival refused to concede and said he’d fight the results in court.

Calderon, a conservative who preached free-market values and financial stability during the campaign, already was reaching out to other parties to build a “unity government.” His opponent, Andres Manuel Lopez Obrador, blamed fraud for his narrow loss in the vote count and called on his supporters to fill Mexico City’s main square Saturday in a show of force.

With the 41 million votes counted, Calderon of President Vicente Fox’s National Action Party had 35.89 percent, or 15,000,284 votes, to 35.31 percent, or 14,756,350 votes, for Lopez Obrador of the Democratic Revolution Party.

Roberto Madrazo, whose Institutional Revolutionary Party controlled Mexico for 71 years until Fox’s victory in 2000, had 22.26 percent, and two minor candidates split the rest.

Supporters of Mexican presidential candidate Felipe Calderon, of the National Action Party, react at the moment when Calderon took the lead during the electoral recount Thursday in Mexico City, Mexico. Calderon's leftist rival, Lopez Obrador, refused to concede and said he'd fight the results in court. See story, page 6A.

Luis Carlos Ugalde, president of the Federal Electoral Institute, confirmed Calderon as the winner Thursday night, several hours after the final vote count was released.

However, the official declaration of a president-elect must come from the Federal Electoral Tribunal, which has until Sept. 6 to announce. Meanwhile, any challenges will go before the tribunal court. The next president begins a six-year term on Dec. 1.

Mexican stocks closed 2.7 percent higher and the peso rebounded Thursday on the news of Calderon’s lead. The markets closed before the count was finished.

But many obstacles remain in Calderon’s path. If his victory is upheld by electoral courts, he will face a Congress dominated by opposition parties, as well as a divided nation that sends millions north to work in the United States illegally.

President Bush’s decision to send National Guard troops to the border has increased tensions in Mexico, as has a U.S. congressional proposal to extend walls along the two countries’ frontier.

National Action Party candidate Felipe Calderon celebrates his presidential victory with campaign supporters Thursday in Mexico City.

Calderon wants to rely on Mexico’s many free-trade accords to create jobs and crack down on rising crime, and says he’ll try to smooth U.S. relations without letting Washington dominate.

“I want to establish a very constructive relationship without bowing my head and lowering my eyes to the Americans,” Calderon said during an interview.

“I have met with President Bush several times. I have interviewed with President Bush and several members of the American Congress, and I know it’s possible to establish a more constructive relationship, and that would be very good for both countries.”