Ulsan, South Korea:Germany did just enough to beat the United States 1-0 on Friday and advance to the World Cup semifinals, but had goalkeeper Oliver Kahn to thank for a string of first half saves. Michael Ballack scored a 39th minute header as three-time champion Germany made it to the last four for the 10th time in its history. Ballack, rising high between U.S. defenders Tony Sanneh and Gregg Berhalter, headed home a right-wing free kick from Christian Ziege. The Americans came close to equalizing in the 49th minute when Berhalter had a header from a corner which appeared to be handled by Torsten Frings right on the line. Referee Hugh Dallas turned away the Americans' furious protests and awarded Germany a free kick for an apparent foul. Germany will play the winner of Saturday's quarterfinal between South Korea and Spain. In the first half, the Americans had looked the most likely to score but couldn't get past the imposing figure of Bayern Munich 'keeper Kahn. Kahn's first came in the 17th minute when he had to dive low to his right to tip away a powerful strike from Landon Donovan from the edge of the area. In the 30th minute, Donovan, playing up front instead of his normal midfield position, latched onto a long ball through the middle and found himself one-one-one with Kahn, but the Bayern Munich 'keeper stood tall and saved. In the 36th, Kahn denied Eddie Lewis who struck a powerful shot from the edge of the area. Germany had struggled with the Americans' pace and tough tackling in the early stages. U.S. skipper Claudio Reyna was winning battles in the middle and twice launched early attacks for Eddie Lewis down the left and Sanneh down the right. When Germany broke, its strikers struggled to break through a back line marshaled by the powerful duo of Eddie Pope and Sanneh. Ballack's goal came against the run of play, but Germany threatened to extend its lead in the 43rd minute, again troubling the United States with its aerial strength. But striker Miroslav Klose seeking his sixth goal of the tournament headed against the post. The Americans looked rattled and Pope and Lewis received yellow cards in the final five minutes of the half. The second half saw the Americans again on the attack, and German Christoph Metzelder had to make a diving header to clear a cross from Lewis that just eluded Sanneh's desperate lunge. In the 64th minute, Kahn cleared with a long header, and Reyna, reacting quickly, tried a spectacular lob from the edge of the center circle but it went narrowly over. U.S. coach Bruce Arena sacrificed defender Frankie Hedjuk for striker Cobi Jones as he desperately sought an equalizer. The game then turned scrappy, and Dallas showed yellow cards to Germans Sebastian Kehl and Oliver Neuville and Americans Pablo Mastroeni, Berhalter and Reyna of the United States within the space of five minutes. The Germans, sensing their best showing since 1990 when they beat Argentina in the final, shored up their defense in the closing stages, launching occasional counterattacks. The United States had a late chance when Sanneh found himself free in the box, but he had his back to goal and could only head well over. In the final seconds, Sanneh again came close, but headed a cross from Clint Matthis into the side netting. Lineups:Germany: 1-Oliver Kahn (c), 2-Thomas Linke, 6-Christian Ziege, 7-Oliver Neuville (17-Marco Bode, 79th), 8-Dietmar Hamann, 11-Miroslav Klose (20-Oliver Bierhoff, 88th), 13-Michael Ballack, 15-Sebastian Kehl, 19-Bernd Schneider (16-Jens Jeremies, 60th), 21-Christoph Metzelder, 22-Torsten Frings. United States: 1-Brad Friedel, 2-Frankie Hejduk (13-Cobi Jones, 65th,) 3-Gregg Berhalter, 4-Pablo Mastroeni (8-Earnie Stewart, 80th), 5-John O'Brien, 7-Eddie Lewis, 10-Claudio Reyna (c), 20-Brian McBride (11-Clint Mathis, 58th), 21-Landon Donovan, 22-Tony Sanneh, 23-Eddie Pope. Referee: Hugh Dallas, Scotland.