A millionaire soccer boss from Argentina's center-right opposition was elected mayor of Buenos Aires in a run-off vote on Sunday, defeating a candidate backed by President Nestor Kirchner.

With more than 73 percent of the ballots counted, 60.5 percent of voters supported Mauricio Macri, a congressman and president of the country's most popular soccer club, while 39.5 percent backed Daniel Filmus, Kirchner's education minister.

"Change won in Buenos Aires today," Macri told a throng of cheering supporters. "It's a change that proposes a different kind of politics, different values."

Macri's victory catapults a leading opposition figure into one of the country's key political posts, dealing a blow to the Argentine leader ahead of this year's presidential election.

Highly popular, Kirchner had waded into the contest, hoping to broaden his power base.

Analysts say the win will likely anoint Macri as the leader of a fractured opposition struggling to gain ground on the center-left president in the October 28 presidential race.

"This affirms Macri as the figurehead of the opposition," Joaquin Morales Sola, a political columnist at the Buenos Aires daily La Nacion, said in televised comments.

Kirchner has dominated Argentine politics since taking office in 2003, consolidating power as he won credit for engineering the country's economic recovery.

BIG LEADS

Public opinion surveys show Kirchner and his wife, a senator, holding substantial leads in the presidential race, with either expected to win easily. Neither has said if they will run, but Kirchner frequently hints his wife may do so.

Macri was widely seen as a potential candidate in the presidential election before he jumped into the mayor's race. He has hinted it might be a first step toward a 2011 presidential candidacy.

Kirchner hand-picked Filmus to compete in the race in Buenos Aires, home to some 2.8 million Argentines and an independent-minded electorate that frequently votes against national trends.

Macri, 48, hails from one of the country's wealthiest and most controversial families. His father, business tycoon Franco Macri, is one of Argentina's richest men whose businesses flourished during the 1990s under former President Carlos Menem.

Kirchner, who blames Argentina's 2001-2002 economic crisis on neo-liberal economic policies implemented during the Menem years, had publicly warned a Macri victory could mark a return of Menem's policies.

In the final days of the campaign, Macri got a public relations boost from his role as president of the Boca Juniors club, where soccer great Diego Maradona once starred.

On Wednesday, Boca won Latin America's Copa Libertadores tournament, the equivalent of Europe's Champions League championship.