Ballack salutes Kahn

Hamann celebrates Ballack's winning goal

Michael Ballack admitted Germany's passage to the semi-final of the World Cup had been anything but plain sailing after they beat the USA 1-0.

Germans beat valiant USA

Ballack scored the only goal of the game with a header in the first half.

But the Germans were under severe pressure for much of the second half, and were thankful to Oliver Kahn for resisting the USA charge.

"The Americans were top, fit and kept trying for 90 minutes, putting us under a lot of pressure," he said.

"They proved their presence in the quarter-finals was no accident. They deserved to be at that stage.

Reaction from the USA camp

"We knew that at set pieces were one of our strengths," the midfielder added.

Michael Ballack scored the only goal of the game

"I'm happy that it works out well but it was a lot of hard work and we also had a bit of luck."

Germany coach Rudi Voeller said he wanted to see an improvement in the semi-finals.

"I'm happy to reach the semi-finals but I'm not 100% happy because we didn't start so well and we didn't play as I wanted us to.

"They put a lot of pressure on us and we didn't get our combination play going.

"Before the World Cup, no one thought we had any chance of doing well, or surviving the first round. We've proved them wrong and I'm happy to have done that.

"We have a very young team but we will have to improve in the semi-finals."

Kahn, who turned 33 last Sunday, played down the importance of his display.

"I'm just happy to have played my part in the victory," he said.

"I have a group in front of me who fought very hard for this."