South Korean manager Cho Kwang-rae was thrilled his side was able to break down Iran's stoic defence in their 1-0 Asian Cup quarter-final victory.

The South Koreans advanced to the semi-finals of Asia's premier national soccer tournament - where they will meet Japan - courtesy of a Yoon Bit-garam's extra-time goal.

Cho said his side's patience paid dividends, as evidenced when Iran's defence failed to shut down the space around Yoon, allowing the 20-year-old to fire the Koreans into the final four.

"The Iranian team's defensive organisation was very strong, especially in the middle where they were very compact and highly organised," Cho said.

"I believe not many teams can score goals against them and if you see figures of their previous matches this is proven."

"To win this game with a clean sheet is the greatest thing a coach can get. In general, the defence was successful tonight and in that respect I was satisfied."

"Regarding the tiredness of the players, it can happen in these tournaments but the most important thing is that the players held on until the end of the game and that was the key factor for me."

The loss marked Iran manager Afshin Ghotbi's last match in charge of the side before he departs to take the reins of J-League club Shimizu S-Pulse.

While Iran beat bitter rivals Iraq in the group stages, Ghotbi was disappointed he could not appease the country's football-mad supporters with a trophy.

"This championship was very important to our players and our team," Ghotbi said.

"When we reached the second phase we started believing we could be champion and make the people of Iran happy."

"When these two sides meet anything can happen. We tried very hard to get the players to relax and play football, but the Koreans did very well in the midfield and closing down space."

"At half-time we talked about it and I think in the second half we improved but not as we would have liked. Again, it comes to the importance of winning and I think it got to the players."

"They are tired of not coming home with the trophy for 35 years and they wanted to do this for the people."