Goal hero Shunsuke Nakamura believes Japan needs to improve further to make World Cup qualification a certainty. After defeating Bahrain 1-0 on Saturday thanks to Nakamura's goal, Japan took one step closer to qualifying for South Africa 2010 but the Celtic playmaker thinks there is plenty of work to be done.

"I don't feel like we qualified yet. We have too many things to improve further. We have to play more scrupulously in every play. We should exchange passes without looking round," said Nakamura.

"It was really tough to take three points from a win. We confirmed it again. It would have been easier if Uchida had scored a goal. He could have hit it to a different angle."