ULSAN, South Korea -- A single goal by Michael Ballack was enough to see Germany squeeze past a spirited United States team here Friday evening, although not without several nasty scares from a U.S. side who refused to be over-awed by its opponents' reputation.

Rudi Voeller's team -- some say it is efficient, others say it is dull -- now move on to Seoul for the World Cup's first semifinal, where they will face either South Korea or Spain, who are to meet Saturday.

"The Americans were very fit and kept trying for 90 minutes, putting us under a lot of pressure," said Ballack who headed the winning goal six minutes before halftime.