Park Chu-Young inspired South Korea to a 2-0 victory over Japan at the Millennium Stadium and a first-ever Olympic football medal.
Arsenal striker Park set them on their way with a superb solo effort in the 38th minute before skipper Koo Ja-Cheol sealed the win 11 minutes into the second half.
Japan enjoyed plenty of possession but, like Great Britain before them, found it tough to break down a well-organised Korean rearguard.
Korea captain Koo was heavily involved from the off and had a penalty appeal waved away when he went down far too easily with Hiroki Sakai in close attendance.
After a difficult start Japan slowly settled, but there was a niggly undercurrent to the game, summed up by Koo's wild lunge on Japan skipper Maya Yoshida, which earned the midfielder a booking.
It took almost half an hour for the first shot on target, with Jung Sung-Ryong unconvincingly parrying Hiroshi Kiyotake's low shot.
Sakai headed over from a corner for Japan, but it was South Korea who took the lead when Park seized on a poor defensive header to brilliantly turn Daisuke Suzuki and fire low beyond Shuichi Gonda.
Yuki Otsu crafted a great chance to level early in the second half, but scuffed his shot after linking with Keigo Higashi.
And the miss was punished seconds later when Sunderland's Ji Dong-Won flicked on goalkeeper Jung's punt downfield to allow Koo to shoot across Gonda into the net.
It was almost 3-0 just shy of the hour but Gonda managed to tip Kim Bo-Kyoung's curling effort onto the post.
Japan pushed forward in search of a way back into the game, but their hopes of setting up a tense finish ended when Yoshida's header was ruled out for a block on Jung with three minutes to go.