Yoon (60), from the main opposition People Power Party, edged out the ruling Democratic Party’s Lee Jae-myung with 48.6% of the vote to 47.8%, with about 99.3% of the ballots counted as of Wednesday evening.

Yoon said he would honour the Constitution and Parliament, and work with opposition parties to heal polarised politics and foster unity, calling the election a “victory of the great people”.

“Our competition is over for now,” he told a news conference, thanking and consoling Lee and other rivals. “We have to join hands and unite into one for the people and the country.”

Lee had conceded defeat and congratulated his opponent.

“I did my best, but failed to live up to your expectations,” he told a news conference, blaming his “shortcomings”.

“The president-elect, I desperately ask you to overcome divisions and conflicts and open an era of integration and unity.”

Despite being a political novice, Yoon shot to fame after spearheading high-profile investigations into corruption scandals engulfing incumbent President Moon Jae-in’s aides.

Yoon has pledged to stamp out graft, foster justice and create a more level playing field, while seeking a “reset” with China and a tougher stance towards reclusive North Korea.

The unusually bitter election campaign was marred by scandals and smears, but more than 77% of South Korea’s 44 million eligible voters cast ballots to pick their next leader.

The policy stakes are high for the country of 52 million with a rising global status, as it has been riven by gender and generational divisions, growing inequality and surging house prices.

Yoon also has to tackle challenges including South Korea’s worst wave of Covid-19 infections and North Korea’s evolving nuclear and missile threats, while navigating an increasingly tense rivalry between China and the United States.

(Reporting by Hyonhee Shin and Jack Kim. Additional reporting by Josh Smith, Daewoung Kim and Yeni Seo. Editing by Nick Macfie.)