The Dutch top their pool at 2010 FIFA World Cup South Africa™ having taken maximum points in their opening two fixtures.
"I think it's an excellent result," said Sneijder, who has earned Budweiser Man of the Match honours in consecutive games. "We have done a great job. It doesn't matter how you play as long as you get the win.
"We have six points and we still have one match to go and we want to finish first in the group."
The Inter Milan playmaker was all the more satisfied considering the Dutch have dominated their opening two games. "We controlled the match against Japan," he added. "Japan are fast and it's difficult to play football against them.
"You need a bit of luck and we got that, and we should have ended up scoring two or three more goals. But the important thing is that we are not giving away goals."
Coach Bert van Marwijk is unlikely to make many changes to his line-up for Thursday's match against already-eliminated Cameroon. He said: "I will look at the fitness of my players and at the yellow cards but I don't plan to make major alterations."
Japan coach Takeshi Okada hopes his side can turn the page as they look to prepare for their final group game against Denmark on Thursday. Both sides go into the encounter level on three points, with one last-16 spot up for grabs.
"We have no time to look back as we have to focus on our next match," said Okada. "Right now my players are shocked but I have no intention of making any major modifications.
"We have to recover physically and mentally so my team will be able to play in the best way against Denmark.
Okada admits his team have to make improvements if they are to progress, saying: "We have to be aggressive in attack. We don't have a powerful centre forward so we have to be quick on set plays and connect well with the ball."