Serbia's pro-EU PM Aleksandar Vucic has claimed victory in general elections after pollsters' projections showed his Progressive Party won 50% of the votes.
He said Serbs "again gave us the honour to lead the government".
Mr Vucic called the poll early seeking a mandate to continue with reforms required to join the EU.
The Socialists are in second place with about 13%, while the ultra-nationalist Radical Party - which seeks closer ties with Russia - is third with 7%.
Radical Party leader Vojislav Seselj could return to parliament after his recent acquittal of crimes against humanity at the UN war crimes tribunal in The Hague.
The Radical Party opposes EU membership.
The initial projections were published by independent observing group CeSID.
After casting his ballot earlier on Sunday, Mr Vucic said he would not compromise with right-wing parties and hoped that voters would choose a "European path".
"I'm almost certain that we'll carry on our EU integration process," he said.
Also voting in Belgrade, retired Jelica Nikolic, 68, said she and her husband were acting more out of duty than conviction. "We have elections too often," she said.
In the south-western city of Novi Pazar, voter Edib Mahmutovic, 40, hoped the winner would create new jobs "that enable us to stay here and not have to look for a better life elsewhere in Europe".
This is Serbia's third parliamentary election in less than four years.
The key players
Serbian Progressive Party (SNS), led by Aleksandar Vucic, centre-right
Founded in 2008, it has been in power since 2012. It won an overall majority two years ago, an unprecedented event in Serbia's short democratic history. It wants to pursue EU membership while maintaining good relations with Russia.
Socialist Party of Serbia (SPS), led by Ivica Dacic, left
Founded in 1990 by Serbia's late strongman Slobodan Milosevic. Its main goals are achieving more social justice, social welfare and finding a political solution for Kosovo. But it has supported austerity policies implemented by its coalition partner SNS.
Serbian Radical Party (SRS), led by Vojislav Seselj, ultra-nationalist
Founded in 1991, promoted since its early days a "Greater Serbia" comprising parts of Bosnia and Croatia where Serbs formed the majority. It opposes EU membership and supports a closer alliance with Russia.
Sources: AP, Reuters
If confirmed, the results would mean an absolute majority for Mr Vucic in parliament.
The ultra-nationalists, however, could complicate Serbia's EU membership talks by resisting concessions, such as ending the claim to sovereignty over Kosovo.
Critics of Mr Vucic say his government has become increasingly autocratic, with some calling him a "dictator".
Serbia has signed a €1.2bn ($1.35bn; £940m) loan with the International Monetary Fund (IMF). In return, it needs to implement austerity measures demanded by the group.
The Serbian economy is in bad shape, and unemployment is at around 18%.