Presidential candidates Tomislav Nikolic (R) and Serbian incumbent President Boris Tadic (L) cast their ballots
Serbia's incumbent president Boris Tadic and nationalist opposition leader Tomislav Nikolic will contest the second round of presidential elections, estimates showed Sunday.
Preliminary estimates based on votes counted in more than 1,000 of 8,000 polling stations by independent monitor CESID show Tadic and Nikolic leading with 26.7 percent and 25.5 percent respectively.
The run-off vote will be held on May 20.
Sunday's vote was seen as a turning point for Serbia because for the first time in almost two decades the election focused on bread-and-butter economic issues rather than the wars that made the country an international pariah.
Tadic, who in his eight years of power managed to steer Belgrade back into the West's favour and secured EU-candidacy status in March, said the run-off would determine the country's future.
"Our policies will speed up Serbia's path towards European integration," Tadic said, adding that he was convinced of a second-round victory.
"I expect even more support from citizens (in the run-off) ... because it is in their utmost interest: to lead them into the EU, to bring more investments, more regional cooperation"
In the parliament Nikolic's Serbian Progressive Party (SNS) had become the biggest party with 24.7 percent of the vote, according to CESID estimates.
However, the difference with Tadic's Democratic Party (DS) which got 23.2 percent was not as big as predicted before the vote.
Analysts said the SNS was able to cash in on voter discontent over low wages and record unemployment in the poor Balkans country.
With neither party having an absolute majority they will have to put together a coalition government.
But the results give the kingmaker role to the Socialists (SPS).
Founded by late strongman Slobodan Milosevic, the SPS doubled its parliamentary presence with 16.6 percent of the vote to become the third biggest party.
Results released by Serbia's electoral commission RIK -- based on just 7.8 percent of the votes counted at over 8,000 polling stations -- confirmed the trends in the CESID parliamentary figures.
They also confirmed that it would be Nikolic and Tadic who face each other in a presidential run-off.
"We have to be proud of the electoral result,..." Nikolic told supporters at his party's headquarters.
"The party, in three-and-a-half years of existence, has won most of the votes in Serbia," he said.
"From tomorrow I want to start talks about (forming) a new government of Serbia ... we have no time to lose."
Nikolic, who has twice been beaten by Tadic in a presidential run-off, was in combative mood Sunday.
"Now I am convinced I will win in the second round," he said.
SPS leader Ivica Dacic, who has pushed the party away from Milosevic's legacy, revelled in his win.
"We still don't know who will be president, but we know for sure who will be the prime minister," he said, referring to himself.
He told his party faithful that he would first talk with Tadic's DS, with whom he has been in the ruling coalition for the past four years.
And since Dacic also got 15.3 percent of the presidential vote Sunday, his endorsement for the second round could be decisive for either candidate.
But Analyst Srbobran Brankovic told RTS state television that coalition talks would not get serious until after the second round.
"Dacic is closer to Tadic, but if the run-off brings Nikolic's victory, other options are open," he predicted.
Nikolic and the SPS have already shared power in the past: in the late 1990s, during the Milosevic era.
The electoral commission has until Thursday to publish the final results of the vote.