Eroglu's triumph was greeted by an explosion of joy among his supporters outside UBP headquarters in northern Nicosia, as fireworks crackled in the night sky.
Al Jazeera's Lawrence Lee, reporting from Nicosia, said the race was close.
"Eroglu needed 50 per cent of the votes outright to claim victory; he's on 50.36 per cent. Of a total population here of 164,072 eligible to vote, 0.36 of one per cent is only 546 votes - that was the margin by which he got over the 50 per cent threshold.
"And so a tiny number of votes have led to these enormous repercussions, many people think this is the death of reunification talks," he said.
Eroglu has given assurances he will not abandon the UN-brokered negotiations, but said he will not actively push for a settlement.
"We want the peace process to continue," Eroglu said while polling was under way.
"There's no question of pulling out of the talks."
He pledged to keep Turkish Cypriots fully informed of developments in peace talks, saying that unlike Talat he was not negotiating "behind closed doors".
Opinion polls had indicated that disappointment at the lack of progress in the peace talks, together with the Turkish Republic of Northern Cyprus' (TRNC) ongoing political and economic isolation, undermined support for Talat.
Tayyip Erdogan, the Turkish prime minister, said on Sunday his country will continue backing peace talks between Turkish Cypriots and Greek Cypriots in the divided island regardless of who wins the election.
He also said he will seek a solution to Cyprus by the end of 2010.
Talat has held 18 months of reunification talks with Demetris Christofias, the Greek Cypriot president and head of the internationally recognised Republic of Cyprus, a member of the European Union.
The talks, launched in September 2008, are predicated on a federal solution, with distinct geographical zones for the Greek Cypriot and Turkish Cypriot communities.
|Opinion polls indicated that lack of progress in talks with the south had harmed Talat [AFP]
Last month, Christofias and Talat announced important progress in the talks and vowed to reach a comprehensive settlement this year in a move that was widely seen as a bid to boost the Turkish Cypriot leader's election prospects.
But the two sides remain far apart on the key issues of property and security.
Eroglu's stance on reunification could, in turn, impact on Turkey's drive for European Union membership, cripple closer EU-Nato security co-operation and keep Cyprus as a source of instability on the EU's frontier with the Middle East.
Cyprus is already blocking parts of Turkey's EU membership negotiation process because of Ankara's refusal to recognise the Greek Cypriot government.
The island of Cyprus split in 1974 into the internationally recognised Republic of Cyprus in the south and the Turkish-held Northern Cyprus. It happened when Turkey invaded the island after a short-lived coup backed by Greece.
The TRNC, with a population of 257,000, is recognised only by Nato-member Turkey, which maintains 35,000 troops there.
The electoral commission in the TRNC put turnout at a 75 per cent.