Santiago Pena secured a sweeping victory in Paraguay's presidential elections on Sunday after claiming 42.7 percent of votes out of 99.9 percent counted ballots.

Pena is the candidate of the country's ruling party, the conservative Colorado Party, which has dominated the political scene since the 1950s. With his win, the party further tightened its grip on the government.

"Thank you for this Colorado victory, thank you for this Paraguayan victory," Pena said in an address to his supporters.

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His opponent, the chief of the Authentic Radical Liberal Party, Efrain Alegre, and the political group's candidate, acknowledged his loss.

Serving President Mario Abdo, along with the Presidents of Brazil and Argentina, congratulated "president-elect" Pena.

The winning party and right-wing candidates also scored major wins in Congress governor elections.

"We have a lot to do, after the last years of economic stagnation, of fiscal deficit, the task that awaits us is not for a single person or for a party," Pena said, calling for "unity and consensus."

"All day we've observed high levels of participation," an observer for the Organization of American States' (OAS) electoral mission stated.

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