The Dutch went ahead in the game but then had to battle back from 2-1 down to take the points, which qualified them from the group, and Robben said that they cannot be as sloppy in possession again if they are to reach the quarter-finals.
"The first half, we just played really bad," Robben told nieuws.nl. "We were just sleeping. We made a lot of mistakes in possession. Actually, everything just went wrong, we weren't in the game.
"We had a lack of focus and concentration. This should not happen during a match. We wanted the confidence that we got from the Spain game to take the win.
"We had to work very hard for the victory. The Australians fought hard as it was their last chance."
Holland's final group game is against already-qualified Chile.