A little-known, far-right populist took the lead in Romania’s presidential election on Sunday, electoral data showed, and will likely face leftist Prime Minister Marcel Ciolacu in a run-off vote in two weeks, an outcome that has rocked the country's political landscape.

Calin Georgescu, who ran independently, led the polls with around 22 percent of the vote, while Ciolacu of the Social Democratic Party, or PSD, trailed at 20 percent.

Elena Lasconi of the Save Romania Union party, or USR, stood at about 18 percent, and George Simion, the leader of the far-right Alliance for the Unity of Romanians, or AUR, took around 14 percent.

After polls closed, 9.4 million people — about 52 percent of eligible voters — had cast their ballots, according to the Central Election Bureau.

The second round of the vote will be held December 8.

Thirteen candidates ran for the presidency in the European Union and Nato member country.

The president serves a five-year term and has significant decision-making powers in areas such as national security, foreign policy and judicial appointments.

Georgescu, 62, ran independently and was not widely known. He outperformed most local surveys, sending shockwaves through Romania's political establishment as he ascended to poll position.

After casting his ballot on Sunday, Georgescu said in a post on Facebook that he voted “For the unjust, for the humiliated, for those who feel they do not matter and actually matter the most.”

Cristian Andrei, a political consultant based in Bucharest, said that Georgescu’s unexpected poll performance appears to be a “large protest or revolt against the establishment.”

“The mainstream political parties have lost the connection with regular Romanians,” he said.

Georgescu lacks an agenda, Andrei added, and has a vague and populist manifesto with positions that are “beyond the normal discourse."

His stances include supporting Romanian farmers, reducing dependency on imports, and ramping up energy and food production.

According to his website, Georgescu holds a doctorate in pedology, a branch of soil science, and held different positions in Romania's environment ministry in the 1990s.

Between 1999 and 2012, he was a representative for Romania on the national committee of the United Nations Environment Programme.

Videos posted to his popular TikTok account, where he has amassed 1.6 million likes, depict him attending church, doing judo, running around an oval track, and speaking on podcasts.

Ahead of Sunday's vote, many had expected to see Simion, a vocal supporter of US President-elect Donald Trump, face Ciolacu in the second round.

He campaigned for reunification with Moldova, which this year renewed a five-year ban on him entering the country over security concerns, and he is banned for the same reason from neighbouring Ukraine. (AP)