Citizens erupted with joy early Wednesday morning as their team progressed to the World Cup's round of 16 for the first time on foreign soil after a 2-2 draw with Nigeria.
Despite the pre-dawn hours, more than 500,000 fans gathered in front of giant outdoor TV screens set up across the country, tensely watching their team lose a first goal but later pull through with two.
Groans and sighs were briefly exchanged when Nigeria equalized with a penalty kick in the 69th minute, but it was far from disheartening, with a draw sending South Korea to the knockout stage. In another Group B match, Argentina beat Greece 2-0, letting Korea stand second in the group ranking.
"It's hilarious," said Kim Yeong-su, 42, who watched the game at Daegu Stadium packed with some 15,000 fans. Daegu, about 300 kilometers southeast of Seoul, is the hometown of striker Park Chu-young, who scored the second goal from a clean freekick.
"The son of Daegu, Park Chu-young, netted the decisive goal," Kim said, as the fans shouted with joy "Dae-han-min-guk!" the country's official name in Korean.
Some 268,000 fans took to the streets in Seoul to cheer on their team overnight, their iconic Red Devil T-shirts turning parks, stadiums and street intersections into a sea of red. Some set up tents around the giant TV screens in Yeouido Park and headed to work straight after the match.
"I go to work in the morning, and these kids go to school," Kim Yeong-o, 39, who built a tent to stay in overnight with his family, said with a smile. "The cheering fever heated up early on, and I couldn't sleep at all."
Students joined in the festive mood despite approaching final examinations, some braving the pre-dawn chills in summer school uniforms so as to be ready for early morning classes.
"I came to see the historic moment," said Lee Chang-hee, a high school student, who traveled to Seoul Square from Incheon with friends. "Exams are important, but we really wanted to cheer on our fighters."
The scenic Haeundae Beach in the southeastern port city of Busan turned red with 30,000 fans celebrating into the daybreak. The operating hours for subways and buses across the country were advanced to accommodate football fans.
South Korea has advanced to every World Cup tournament since 1986 but has never made it to the round of 16 except in 2002, when the country co-hosted the games with Japan. Korea then reached the semi-finals.
With Ki Sung-yueng's assist for the first goal, his mother described auspicious dreams by the family.
"Last night, I had a pleasant dream of dancing in Hanbok (traditional Korean clothing)," said Nam Yeong-suk, 50, who watched the game with relatives at home in Gwangyang, South Jeolla Province. "I talked to my brother over the phone, and he said his dream was giving a press conference in flashing lights."