"Victory is ours," Thaçi, without a tie and with his sleeves rolled up, told supporters shortly before midnight. "The elections were a referendum on the European future of Kosovo."
The Gani Bobi polling agency said a survey of more than 2,000 voters leaving voting stations put the PDK on 31% and the LDK, the PDK's main coalition partner in the outgoing government, on 25%.
The PDK, or the Democratic Party of Kosovo, is the largest party in Kosovo. Its political orientation is social democratic. It is led by Hashim Thaçi, the political leader of the former KLA, the Kosovo Liberation Army. The LDK, or the Democratic League of Kosovo, is the second largest party in Kosovo, and is of centre-right ideology.
With almost a third of the votes counted, the PDK had secured 34% and the LDK 25%, according to a group of non-governmental organisations following the count.
Such results mean Thaçi will once again have to seek backing from smaller parties as he prepares for crucial talks with Kosovo's former master Serbia, which does not recognise Kosovo's independence, on practical aspects of coexistence.
Both leading parties seek EU and NATO membership for Kosovo and want to continue privatising state enterprises, but both are short on concrete details of how they will boost one of the poorest economies in Europe.
In the last election in 2007, the PDK won 34.3% of the vote with the LDK securing 22.6 percent. Sunday's turnout was 47.8%, according to the election commission, slightly up on 2007.
The biggest surprise was the strength of the Self-Determination Movement, which was runing for the first time on a mandate of uniting Kosovars with their ethnic kin in neighbouring Albania. The exit poll put it in third place on 16%.
It also wants to reduce international controls over Kosovo, which is still an international protectorate, and stop the privatisation process.
The LDK has said it does not want to renew its coalition with Thaçi's party, which could mean a say in government for the Self-Determination Movement or other smaller parties.
The European Union and the United States view the snap election as a test of Kosovo's democratic maturity, and a free and fair vote is a condition for eventual membership of the EU.
"I consider the voting process a success," said Valdete Daka, head of the Central Election Commission. "There have been technical hitches that have not hurt the process."
However, ethnic Serbs in the divided town of Mitrovica boycotted the election, showing that tensions still linger following Kosovo's breakaway from Serbia.
"These elections were organised by a state that does not exist for me and this is the reason why I don't vote," said Dragan Vukosavljevic, a Serb in Mitrovica, whose northern half - like much of northern Kosovo - is outside Pristina's control.
But in the largely Serb village of Gračanica, close to Pristina, voters appeared to have turned out in numbers to vote for one of the nine Serb parties that ran.
Many Albanians interviewed outside polling stations said they hoped for change. Since the rallying goal of independence was realised in 2008, Albanians have been less reverential about their leaders as they face the tough reality of building a nation during an era of world economic crisis.
"I would like to see more courageous leaders who keep their word," said Fatime Sheremeti, 47.
According to BETA agency, EurActiv's partner in Serbia, the turnout in the Serb-populated area stood at 11%. The turnout across Kosovo was 47.8%, the same sources indicated.
A Commission spokesperson said on 9 December that the EU hoped that the elections would be free and fair and that people would vote massively, including in the Serb-populated areas.
(EurActiv with Reuters.)