In the middle of the June 3 local election count, Oh Se-hoon of the People Power Party, who had trailed Democratic Party of Korea Seoul mayoral candidate Chong Won-o, pulled off a dramatic comeback at the very end of the count. As the count continued after the reversal, the gap widened, making Oh's victory all but certain. Chong said, "I solemnly and humbly accept the choice of the citizens," acknowledging defeat.
As of 9:37 a.m. on the 4th, with 97.7% of the ballots counted, Oh had received 2,501,865 votes, leading Chong (2,471,506 votes) by more than 30,000. Oh's vote share was 48.94%, ahead of Chong's 48.34% by 0.6 percentage point(s).
In the early stage of the count, which began around 6:20 p.m. on the 3rd, Chong led Oh by more than 30 percentage point(s). Even after the count surpassed 50%, the gap between the two remained over 20 percentage point(s). At the time, based on exit polls by the three major broadcasters, Chong was expected to win.
This trend began to narrow after 2 a.m. on the 4th. After shrinking to a 5 percentage point gap, it rapidly narrowed to a 1–2 percentage point difference around 5 a.m. After 6 a.m., it tightened to around 0.5 percentage point, and at about 7:17 a.m., a "golden cross" occurred as the two candidates switched places.
After that, the gap between the two candidates continued to widen.
On the morning of the 4th, Chong acknowledged defeat and congratulated Oh on the victory. Chong said, "I am sorry for failing to meet the expectations of the citizens who trusted and stood with me, as well as the camp officials and party colleagues," adding, "I extend my congratulations to the winning candidate, Oh Se-hoon."
Oh was set to move soon to the campaign office in Jongno, Seoul, to deliver his victory remarks. Oh said, "This election result is the victory of the citizens," adding, "I will devote all my capabilities over the final four years for Seoul."
However, regarding this Seoul mayoral election, the National Election Commission's poor management is expected to come under scrutiny. This is because at 12 polling stations in Songpa-gu, one in Gangnam-gu, and one in Gwangjin-gu, a shortage of ballots forced voters to wait or turn back.