Serbia's centre-right Progressives, a party of former ultra-nationalists converted to the cause of European Union membership, have won an outright majority in parliament, according to an estimate.
The margin of victory, rivalling the results of the late Slobodan Milosevic during the war years of the 1990s, will see Progressive Party (SNS) leader Aleksandar Vucic become prime minister as Serbia embarks on talks to join the EU.
"No one has had such a day," Vucic told cheering supporters in Belgrade, according to a Reuters news agency report.
"My goal is not to be rich, my goal is for the people of Serbia to live better," he said.
The SNS forced the snap election after just 18 months in coalition government with the Socialist Party of outgoing Prime Minister Ivica Dacic, saying it needed a stronger mandate to overhaul Serbia's shaky finances.
Pollster Cesid said the Progressives had won 48.8 percent of ballots cast, which under Serbia's electoral system would translate into around 157 seats in the 250-seat parliament. The party itself said it had won 49.3 percent.
According to Cesid, the Socialists came in second with 14 percent, securing about 50 seats.
The rest of the seats went to the pro-Western Democratic Party and the New Democratic Party of former President Boris Tadic, the two groups that split up before the vote.
It was one of the most convincing victories by a party since the multiparty system was introduced in Serbia in the 1990s.
In his victory speech, Vucic pledged to vigorously fight against corruption and crime, and revive the economy in the troubled Balkan nation of about 7 million people.
"We are facing tough reforms," Vucic said. "But, I am sure that Serbs will soon live better than they are living now."
Turnout was about 52 percent, slightly less than during the 2012 parliamentary election that brought the Progressives, former allies of Milosevic, back to power, the Associated Press news agency reported.
The vote came as Serbia, a longtime international pariah for fomenting wars in the Balkans in the 1990s, is officially seeking entry into the EU, amid deep economic problems and simmering social discontent because of plunging living standards.
Serbia this year opened membership talks with the EU after signing a deal normalising ties with Kosovo, a former province which split in 2008, but whose independence Serbia's refuses to recognise.
Vucic says he needs a strong mandate to carry out painful reforms needed to help Serbia's economy, which has been ravaged by mismanagement, wars and international sanctions.
The opposition has accused him of seeking to introduce what it calls a Russian-type leadership in Serbia by assuming dominant powers in the state, which is deeply split between pro-Russian and pro-Western sentiment.