SEOUL - South Korea's icon of justice Yoon Suk-yeol has won one of the closest presidential races in the country's democratic history.

The candidate from the conservative opposition People Power Party, who rode on a wave of anti-government sentiment and desire for regime change, won 48.5 per cent of the vote on Thursday morning (March 10), just 0.7 percentage point ahead of main rival Lee Jae-myung of the ruling Democratic Party.

"Rather than a victory for me and the PPP... today's result is a victory for the people," said Mr Yoon. 

"Now that the race is over, we must all work together to become one."

With all ballots counted as at 6.21am local time (5.21am Singapore time), Mr Lee had 47.8 per cent of votes, according to the National Election Commission (NEC).

The difference between the two candidates is merely 247,077 votes.

Mr Lee conceded defeat just before 4am in a statement read at the party's headquarters. He congratulated Mr Yoon and urged him to unite and heal the country.

Mr Yoon, 61, will become the first former prosecutor to be elected president in South Korea. He has no prior political experience.

First rising to fame in 2016 for leading investigations against impeached former president Park Geun-hye, who was embroiled in a massive corruption and power abuse scandal, Mr Yoon had campaigned on the need for regime change.

He advocated fairness and justice, riding on growing public anger against the incumbent Moon Jae-in administration's unfair practices, such as appointing scandal-plagued figures as justice minister.  

His triumph will mark the first time in South Korea's democratic history that the ruling party failed to win presidential elections for a second term. Power used to shift in 10-year cycles, or after two terms.

President Moon is constitutionally barred from seeking re-election.

About 34 million people voted in this election, which translates to a turnout of 77.1 per cent, according to the NEC.

Two exit polls released on Wednesday night showed the race to be neck and neck, projecting a less than one percentage point difference in votes for the two main candidates.

Experts said the razor-thin margin means the country is sharply divided and warned that Mr Yoon could face a rocky road ahead trying to unite the two different camps.

Dr Lee Seong-hyon, visiting scholar at Harvard University’s Fairbank Centre, said many people viewed the election as a judgment on President Moon and his failed policies.

These included property reforms that inadvertently caused house prices in Seoul to double and a 40 per cent hike in minimum wage that caused small businesses to suffer.

"In that sense, President Moon was Lee's biggest liability. It put Lee in an awkward position; on the one hand, he needed the blessing of Moon, but on the other hand, he needed to keep a distance from Moon's policies," Dr Lee told The Straits Times.

"Yoon was elected not because he was qualified enough, but out of the public's dissatisfaction with the Moon government. As president, he should improve the things that the Moon government was criticised for. He should take on the government with a great sense of responsibility and duty, and strive to create a fair society."

Mr Shawn Ho, associate research fellow at the S. Rajaratnam School of International Studies (RSIS) at Nanyang Technological University, said the election results show that South Korea is a politically divided and polarised country.

"Yoon will have his hands full trying to win over the support of the millions of South Koreans who did not vote for him," he told ST.

Experts also voiced concern on the diplomacy front, pointing out that Mr Yoon, due to a lack of experience, will likely toe the party line in strengthening South Korea's alliance with the United States - which could rub China the wrong way.

Mr Yoon has, for instance, voiced a need to deploy another American Terminal High Altitude Area Defence (Thaad) anti-missile system to deter North Korea. The 2016 installation of the first Thaad battery in South Korea triggered massive economic retaliation from China that lasted nearly two years.

"Yoon needs to brace himself for backlash from Beijing as he seeks to bring South Korea closer to the US," said Asia specialist Sean King of New York-based consulting firm Park Strategies.

"Another challenge could be to reassure the Biden administration, and the rest of the free world, that South Korea stands firmly with the US against Russia when it comes to Ukraine."

Mr Ho of RSIS raised concern that the Moon administration's good work in trying to engage North Korea "will likely be abandoned".

"The Yoon administration will take a much harder line towards North Korea and demand that it completely and irreversibly denuclearise before any talk of sanctions relief," he said.

Mr Ho added that South-east Asia might also be a lower priority for the new government, which would be a pity as the incumbent Moon administration had successfully elevated Asean-Korea relations to an all-time high due to its New Southern Policy aimed at deepening ties with South-east Asian nations.

The Yoon administration will also need to deal with challenges such as the economic recovery post-pandemic and the climate crisis and, at the same time, contribute to the international community, noted associate professor of international studies Leif-Eric Easley at Ewha Womans University.

He said South Korea may "struggle to pursue policies of reform rather than politics of retribution" after a divided election, but with democratic resilience at home, its international role can start to grow.

Promises of good jobs, new homes, fair opportunities

Mr Yoon Suk-yeol promised to create good jobs and fair opportunities for the people yesterday in his first remarks as president-elect.

He told reporters at the national assembly yesterday that South Korea faced "an unprecedented and enormous challenge" ahead due to the Covid-19 pandemic, a polarised economy, and low growth rates.

Shifting focus from government-led to what he called a "private-centric economy" would help to create good jobs and strengthen the middle class, he said.

Mr Yoon also promised extensive support for tech innovations, so South Korea could emerge as a leader in science and technology.

"We will usher in an era of unity and prosperity," he said.

During campaigning, Mr Yoon also promised to stabilise skyrocketing property prices by supplying 2.5 million new homes before 2026, including up to 1.5 million in Seoul and its surrounding areas.

He also plans to tackle the country's plunging birth rate. The country's total fertility rate - the number of children a woman could bear in her lifetime - hit a record-low of 0.84 last year. This is already the lowest in the world, and is expected to fall further to 0.7 in 2024.

His plans include increasing medical subsidies for women and a new parent subsidy of one million won (S$1,107) a month for 12 months.

On education, he has spoken of the need to embrace a transition to a digital schooling system that is open, innovative and autonomous.

On diplomacy and national security, Mr Yoon yesterday said that he would strengthen the alliance with the United States, work for better ties with Japan and leave the door open to inter-Korean dialogue while stressing the need for a strong defence force.