The impoverished rebel Georgian region of South Ossetia voted for a new leader Sunday in a tightly-contested run-off damned as illegitimate in the West but closely watched by Russia.

The first round on November 13 failed to produce an outright winner after local emergencies minister Anatoly Bibilov -- backed openly by the Kremlin -- and ex-education minister Alla Dzhioyeva each collected around 25 percent of the vote.

An exit poll conducted by the Moscow-based Higher School of Economics and the Institute of Social Marketing showed Bibilov winning an extremely close ballot with 53 percent of the vote.

The first official results were expected at 9:00 am Monday (0500 GMT) following strong turnout of more than 60 percent.

Bibilov's inability to claim anything close to an overall majority was a major surprise after his candidacy was backed both by visiting Russian President Dmitry Medvedev and South Ossetia's outgoing leader Eduard Kokoity.

Analysts said his candidacy may have suffered because of the region's slow recovery from a devastating 2008 war between Georgian and Russian forces that turned South Ossetia into a effective Moscow protectorate.

Bibilov turned a deaf ear to such criticism as he and his family cast their ballots only metres away from a campaign poster showing him shaking hands with Medvedev -- an image plastered throughout the tiny capital Tskhinvali.

"The republic's future must be as bright as it is today," the local official news agency quoted Bibilov as saying.

His rival Dzhioyeva for her part associated Bibilov with the current Moscow-backed regime and vowed to "scale this mountain ... and lead people to a positive future".

The elections were the first leadership polls in the statelet since Russia recognised it and fellow breakaway region of Abkhazia as independent following a five-day war with Georgia that froze the two sides' ties to this day.

The European Union and the United States both dismissed the first round of polls as illegitimate while Georgia denounced them as a "cynical act of pseudo-democracy".

The electorate in South Ossetia is also tiny: the rebel authorities say its population is 70,000 -- a small figure that Georgia claims is still inflated because of the expulsion of ethnic Georgians and migration.

Bibilov's candidacy benefited from a personal visit ahead of the first round by the Russian president and a strong vote of support from outgoing leader Kokoity -- a former wrestling champion who made no secret of his hostility toward Dzhioyeva.

He told Russia's Komsomolskaya Pravda it was "excluded" that a woman could win the presidency of his republic.

"We have good relations with women in our society. But the Caucasus are the Caucasus," he said.

Bibilov mentioned at various stages of the campaign that he favoured South Ossetia becoming a part of Russia and uniting with the neighbouring region of North Ossetia -- a prospect that risks again fanning tensions with Georgia.

Ossetians are a mainly Orthodox Christian people who speak a language distantly related to Persian and whose territory was split by the breakup of the Soviet Union in 1991.