Germany coach Jurgen Klinsmann has warned his team they need to play at their very best if they are to have any chance of winning the World Cup.

The hosts clinched top spot in Group A with a 3-0 win against Ecuador thanks to a Miroslav Klose double and a Lukas Podolski strike, but Klinsmann admitted his players would find it far harder in the knockout stages.

"The goal of group winner is achieved. I am happy to sample the great atmosphere and with the points we have racked up but we must keep our feet on the ground," he said.

"The team know if we play to our full potential we need fear no one, but we must keep our feet on the ground.

"We won't be allowed a single mistake in the games coming up. The tournament is up and running in earnest now."

Ecuador coach Luis Fernando Suarez was annoyed about his side's lacklustre display and admitted they would struggle to reach the quarter-finals if they performed as poorly next time out.

"We need to improve if we want to go any further in this World Cup. I am disappointed because we did not play a good match." Suarez said.

"We can learn a lot and hopefully won't make the same mistakes again.

"Germany played a great match. It was not what we have expected and we did not play as well as in the first two matches.

"Everybody played badly so we will have to make huge progress in order not to repeat them."