(Reuters) - Buoyed by the initial success of a riveting World Cup, Brazilian President Dilma Rousseff took aim on Monday at critics who said her country would not be able to pull off hosting the world's biggest sports event.

"We are scoring lots of goals against the pessimists who said it would be chaos," Rousseff said after opening a state hospital in Rio de Janeiro.

"Brazilians should feel very proud because, in fact, this country is hosting a fantastic World Cup."

The costliest World Cup to date was plagued by delays in building soccer stadiums, upgrading airports to handle several million fans and improving urban transit.

Critics said Brazil had bitten off more than it could chew by having 12 venues instead of eight.

Rousseff's popularity took a pummeling last year when Brazilians took to the streets in massive street demonstrations to protest the $11 billion price tag for hosting the World Cup, money that many said should have gone to improving Brazil's inadequate education, health and public transport services.

But the protests fizzled out as World Cup fever caught on in the soccer-loving nation and Brazilians flocked to stadiums or became glued to television sets to watch thrilling games that have provided plenty of goals as well as unexpected upsets.

While hosting of the World Cup has been far from perfect, it has gone more smoothly than many expected and with no major embarrassments for the government, boosting Rousseff's chances for re-election in October. [ID:nL2N0OX1EL]

Rousseff, who was jeered at the opening game of the tournament on June 12 in Sao Paulo, has seen her approval rating fall in recent months, but she is still favored to win a tough election race.

With success so far in organizing the World Cup, Rousseff is now hoping for Brazil to win the trophy.

"We here are all big soccer fans," she said. "Now we all have to cheer for a justly deserved victory on the field as well."