But he wasted no time in reflecting on Japan's surprise 1-0 victory over Group E rivals Cameroon on Monday and instead zeroed in on the next game against the Netherlands.
"Tired, to be honest, that's what I felt. Our players have done a good job but what we have to do against the Netherlands was the immediate thought that I had after the game," he told reporters after the final whistle blew.
Keisuke Honda's 39th-minute strike secured Japan's first World Cup victory on foreign soil and followed a barren spell in which they had scored just one goal in five matches. They had even been booed by the own normally polite fans.
Okada, who writes poetry and says he wants to retire and be a farmer after this tournament, was pilloried for eschewing Japan's usual attack-minded style and building on the defence.
His prediction that the Blue Samurai would reach the semi-final was mocked as a poet's idle dreaming.
Following the Cameroon win, he is calling for more steel from his players in the Netherlands match.
"Our defence have done well but we need to be more aggressive to go up in the next game. This is the first win for us on foreign soil, but this is not an achievement for us at all, what is coming next is the point."
Okada had pushed midfielder Honda up into the lone striker's role and it paid off when he slotted in the ball at close range from Daisuke Matsui's cross. The coach also seemed to have transmitted some of his cool to the blonde-dyed player.
"When I was able to make that goal the position and the ball was very good. I told myself to be calm enough to make it because recently we have had these chances and missed them," Honda told reporters.
"Recently our team has not been delivering very good results and to be honest the mood was not the best but with our coach as the focus of our team we have delivered our best and this very good result today."
KUDOS TO DEFENCE
Japan can also take heart from a superb performance in defence by Yuji Nakazawa and Brazilian-born Tulio, who were unphased by Cameroon's powerfully-built three-man strike force and neutralised Samuel Eto'o.
Honda paid tribute to his teammates.
"Our defence has been constantly good in recent matches and today it went well. I really appreciate the efforts made by our the defence."
Japan take on group favourites the Netherlands - who beat Denmark 2-0 in their opener - in Durban at the weekend. The decisive battle for the Blue Samurai is likely to be the meeting with the Danes in Rustenburg on June 24.
Even Japan's ruling Democratic Party, which also been under fire recently, took heart from the performance.
"Instead of being disheartened by harsh criticism, the coach, players and fans joined as one to seize victory," Deputy Chief Cabinet Secretary Motohisa Furukawa said in Tokyo.
"This cabinet also wants to join as one team, listen to the voice of the people and achieve solid results."
Japan's only two previous victories in the finals came in 20
