The Samurai Blue put poor form in the build up to the tournament behind them with victories over Cameroon and Denmark in Group E to seal their place in the last 16 for the first time ever on foreign soil.
Okazaki opened his FIFA World Cup account when he came off the bench to score the clincher in the 3-1 win over the Danes on Thursday, and the Shimizu S-Pulse forward believes if Japan can continue to fight as they have so far they have every chance of victory against Paraguay.
''We didn't have a South American team in our group and I expect there will be fiercer tackling for the ball and the most important thing is that we don't lose those battles,'' he said. ''We have been winning those battles and that is how we have got this far. If we stay confident then I think we can keep winning. We have got nothing to lose.''
Okazaki's first FIFA World Cup goal came as a relief for the 24-year-old, who finished as the world's top international scorer for 2009 with 15 goals. Since the turn of the year, however, he has struggled to match that form, but after getting off the mark on Thursday he is determined to add to his tally in South Africa.
''After getting a lot of texts from my friends it sunk in (that I had scored at the World Cup) and now I am hungry for more," he added. "I have got an image of how I want to play at this tournament."