Alberto Zaccheroni's men have claimed a dramatic first triumph at the EAFF event, beating their neighbours and rivals the Taeguk Warriors to deny China
Japan have won their first East Asian Cup in dramatic fashion, beating hosts South Korea 2-1 thanks to Yoichiro Kakitani's injury-time goal.
China had defeated Australia 4-3 earlier on Sunday, meaning a 1-1 draw between Japan and the hosts would have bizarrely seen the tournament settled on a disciplinary tie-break.
However, Kakitani's effort in the 91st minute at Jamsil Olympic Stadium saw Alberto Zaccheroni's men top the four-team competition by two points from China, with South Korea third and Australia in last spot.
After seeing off some early pressure from the hosts, Japan took the lead in the 25th minute through Kakitani, who beat the offside trap, collected a hopeful long ball from Toshihiro Aoyama and finished well past Jung Sung-Ryong.
It took just eight minutes for South Korea to hit back, Yun Illok cutting inside and dispatching a brilliant, curling effort over Shusaku Nishikawa from all of 30 metres out, a clear contender for goal of the tournament.
As the pressure mounted and conditions took their toll, both teams were restricted to half-chances after the break.
On the hour mark Yojiro Takahagi almost played Kakitani through on goal, but South Korea's defence were able to perform a hurried clearance.
Five minutes later, Lee Seung-Gi was played in behind Japan's backline, but miscontrolled at the crucial moment, allowing Nishikawa to gather.
It looked very much as if the decisive goal would not arrive, raising the prospect of a tally of the yellow and red cards picked up by China and Japan being the determining factor in who would take home the title.
However, Kakitani had other ideas, following in Genki Haraguchi's shot from a lightening counter-attack and curling an ice-cool finish beyond a stranded Jung, the queue for wild celebrations among the Japanese players and substitutes.
That goal saw Kakitani finish the competition as top-scorer, while Japan lifted the title for the first time in five attempts since the tournament's inception in 2003.