Germany beat Russia in the World Team Cup on Friday to book a place in the final.
Philipp Kohlschreiber sealed the host nation's eighth appearance in the final - against defending champion Argentina on Saturday - with a 2-6, 6-3, 6-2 win over Mikhail Youzhny, building on Philipp Petzschner's victory over Igor Andreev on Thursday.
Although Serbia also defeated Spain to leave both countries with a 2-1 record from the round-robin stage, Germany topped the Blue Group and advanced to the final on the basis of having beaten Serbia during the round-robin stage.
''It feels great for sure to be in the final,'' Kohlschreiber said. ''After the first set it didn't look too good, but at the end I'm really happy.
''We had a really tough group and knew everybody could beat everybody, so for sure (we're) very happy to be in the finals.''
Argentina, which beat the United States on Thursday to head the Red Group, is bidding to become the third nation to successfully defend its title after the United States in 1984-85 and Chile in 2003-04.
The South Americans will be playing in the final for the seventh time and have been crowned champions on four occasions, with both defeats coming against Germany, in 1989 and 2005.
Germany also has four wins since the event began in 1978, and both nations will be attempting to become the first to lift the trophy for a fifth time.
