Two goals from Ji Dong-won plus strikes from Koo Ja-cheol and substitute Son Heung-min saw Korea comfortably outclass their opponents at a wet Al Gharafa Stadium.
However, they wasted a veritable hatful of chances, hitting the woodwork twice and seeing five efforts cleared off the line to finish second in Group C on goal difference following Australia's 1-0 win over Bahrain.
That means a quarter-final tie against Iran instead of perhaps an easier route to the last four but Cho underlined that to win Asia's premier competition, you have to beat the best along the way.
“I don't worry so much about the chances we missed tonight,” he said.
“When it comes to Iran, they are one of the powerhouses of Asian football so we'd likely have to beat them at some point to win the tournament. My concern was that I wouldn't have the three players available for the game as they were on one yellow card.
“I intentionally left out Lee Jung-soo while Cha Du-ri and Ki Sung-yeung only played the first-half to prepare for the game against Iran. There are no weak teams in the quarter-finals so we have to prepare to have the team in the best condition.
“I am quite satisfied about the result of tonight's match, we had chances to score many goals but I was happy with the players' attitude towards the game, they took it seriously and did their best.
“We gave a penalty away in the first-half, which we could have avoided. Kwak (Tae-hwi) was not calm enough, so that could be better. All the players did a good job against an organised side, we created many chances, we are getting better and I have been satisfied throughout the tournament.
“If we can continue these performances, I believe the team will do an excellent job for the quarter-final match.”
Cho also feels Iran hold no fear for his side even though Team Melli edged a friendly between the two in September last year 1-0.
“I've seen the Group D games and I'm comfortable about meeting Iran because we played a friendly match in Seoul and if you compare our team from then, we're much better now,” he added.
“I believe we can control the game against Iran.”