Shinji Okazaki has warned Paraguay that Japan have "nothing to lose" as they bid for a historic place in the World Cup quarter-finals on Tuesday.
Okazaki opened his World Cup account when he climbed off the bench to score the clincher in the 3-1 Group E win over Denmark on Thursday to seal Japan's place in the last 16 for the first time on foreign soil.
He said: "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. We have got nothing to lose."
Okazaki's first 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, the Shimizu S-Pulse striker 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."