Takeshi Okada believes that Japan's progress into the second round of the World Cup was down to winning their opening match of the competition against Cameroon.
Keisuke Honda was the hero on that day, netting the only goal in Bloemfontein, to help the Blue Samurai to a narrow win.
They lost their second match against Holland to lose by the same scoreline and, needing only a draw against Denmark in Rustenburg on Thursday night, they produced a strong display to come out 3-1 victors.
"Every victory in the World Cup can never be forgotten," Okada said. "For me, the opening match against Cameroon was very important. If we had not won that match, then everything else would not have been possible."
CSKA Moscow midfielder Honda was again the key figure in securing their progress on Thursday night. His stunning 30-yard free-kick opened the scoring at the Royal Bafokeng Stadium, while another set-piece from Yasuhito Endo and a Shinji Okazaki effort took them to victory.
Okada felt the win over the Indomitable Lions also gave the players confidence after a poor build-up to the competition and is now confident they can kick on.
He continued: "We were able to win the opening game and that also gave the players a lot of confidence. In saying that, even before the World Cup, our players had been really good, but we weren't getting the desired results.
"But here at the World Cup we have been able to do that. Looking at the three matches so far and the recent friendly matches, we still can't play on an equal footing with the bigger teams."
Denmark coach Morten Olsen thought his side were just as good as their opponents, but said the free-kicks had undone them.
"We lose together as a team and we win together as a team," he said. "I don't think we played a bad match, but those two set-pieces were the main difference between the two sides
"Of course as a coach you don't want to concede free-kicks in such areas. We prepared for them. We knew exactly which two players would take them.
"They took their chances, we didn't take ours and it became an uphill struggle for us. The way the whole match evolved was decided by the two free-kicks in the first half."
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