Korea's captain Son Heung-min almost opened the scoring seconds into extra time when he took advantage of an error by Japan's Teruki Hara who lost ball possession in his own defense.
Son, 26, current Asia's biggest talent in the English Premier League, celebrated the win by making a victory lap carrying South Korea's flag and approached his fans in the stands, who greeted him with sheer jubilation.
Elsewhere, China dashed the hopes of Unified Korea for an emotional women's basketball gold medal when they won a tense final 71-65 on Saturday.
South Korea's center Park Ji-su had a double-double with 10 points and 11 rebounds, while three other teammates, including North Korean star Ro Suk-yong delivered 17 points to secure at least a silver medal in Jakarta.
"I might have said a few harsh words to my teammates, but they did not take it the wrong way as they knew what needed to be done".
"I really want to say thank you to the coach, the players and fans of Spurs".
"I feel we didn't have enough time to practise together", said Lim Yung-hui, the game's top scorer with 24 points. We worked so hard. "They are so special". Now I am looking forward to getting back to England and showing what I can do'.
Last season for Spurs, Son found the back of the net 18 times while providing 11 assists across 53 appearances.
Those without a chance of a presidential pardon have turned to more drastic measures - many young men intentionally gain or lose weight, feign mental illness, get full body tattoos or resort to self-harm in order to get an exemption, according to the Yonhap news agency. The stress is gone; he only has to worry about one thing. Plus after this weekend's fixtures, everyone gets an global break. "We can win a gold medal against South Korea if we take them head-on with all our strength".