Teenager Sabine Lisicki stunned former world number one Lindsay Davenport 6-1 7-5 to give Germany a surprise 1-0 lead over the United States.
The 130th-ranked teenager produced one of the biggest upsets in the history of Fed Cup defeating the former Wimbledon, US Open and Australian Open champion in straight sets. Previously, Davenport had won 25 of 27 singles matches in the team competition.
"Lindsay is such a great champion and I just beat her," said excited Lisicki after the biggest victory of her career.
"We're 1-0 up and I think nobody thought that it would be that way," added the 18-year-old German, who reached the third round of last month's Australian Open after winning three qualifying matches.