South Korea held 10-man Japan to a 0-0 draw to win the East Asian soccer championship in Yokohama on Wednesday.
Both teams finished level with seven points from three games at the inaugural four-team competition but the South Koreans took the title on a superior goal difference.
Japan striker Yoshito Okubo was sent off after just 18 minutes after receiving his second yellow card for diving at International Stadium Yokohama.
Both sides had numerous chances to win but neither could convert them into goals.
Earlier in the day, two goals in a minute from Zhao Xuri and Liu Jindong put China on the way to a comfortable 3-1 victory over Hong Kong, China, at the same venue.
Both teams were playing for pride after losing their first two games, with China finishing third in the table on three points and Hong Kong, China, at bottom.