Caracas, Venezuela (BBN)-The opposition in Venezuela has won a majority of seats in the National Assembly, overturning nearly two decades of dominance by the Socialists of President Nicolas Maduro.
Five hours after polling ended, the National Electoral Council announced the opposition had won 99 seats, reports BBC.
President Maduro has admitted defeat, recognising "these adverse results".
It is the worst-ever defeat by the leftist movement founded by former leader Hugo Chavez in 1999.
The Socialists have gained 46 seats, with another 22 yet to be declared.
Results arrived much later than expected, five hours after polls closed.
Fireworks erupted over the capital, Caracas, soon after.
Among the campaign issues were chronic food shortages of staples - such as milk, rice, coffee, sugar, corn flour and cooking oil.
Maduro has blamed the situation on an "economic war" waged against his government by the opposition.
The opposition alliance, made up of centrist and conservative parties, is confident of ultimately taking at least 112 seats after 16 years of socialist control.
According to senior figures in the alliance, that would allow them to pass laws allowing the release of political prisoners and to reverse, for example, appointments to senior legal positions made by the current government, says the BBC's Wyre Davies, in Caracas.
It also gives stronger momentum to the opposition should it wish to call a referendum on Maduro's future.
This could take place only when his presidency reaches its halfway point in April next year.
"The results are as we hoped. Venezuela has won. It's irreversible," tweeted Henrique Capriles (in Spanish), a leading opposition figure in the Democratic Unity Roundtable and a former presidential challenger.
However, under Venezuela's presidential system the United Socialist Party of Venezuela (PSUV) will still be a powerful force, as it controls many municipalities.
Why does the result matter?
It is the first time in 16 years that the PSUV is not in control in Congress - a serious blow to its socialist revolution
At 74.3 per cent, voter participation was high, suggesting a sizeable proportion of the population backed change
The opposition will pose a serious challenge to the government's power to pass legislation
Jailed opposition leaders could be released if the opposition makes good on its promise to pass an amnesty law
It is another blow to left-wing policies in Latin America, coming two weeks after a centre-right candidate won in Argentina's presidential poll
The elections were widely seen as a referendum on President Maduro, the handpicked successor of the late President Hugo Chavez, and the party's socialist policies.
The opposition accused the PSUV of mismanaging the economy and of squandering the country's oil wealth.
Maduro says his party defends the interests of ordinary Venezuelans and wants to complete Chavez's "Bolivarian Revolution".
The opposition also accused the government of increasing authoritarianism.
Earlier this year, opposition leader Leopoldo Lopez was given a 13-year prison sentence for inciting violence - a charge critics say was politically motivated.
Venezuela invited election monitors from regional body Unasur but rejected those from the Organization of American States (OAS) and the European Union.
BBN/SK/AD