Defending champions Argentina levelled the World Team Cup final 1-1 against Germany on Saturday in the singles after Juan Ignacio Chela beat Philipp Kohlschreiber in straight sets.
Chela earned a 6-4, 7-6 (7/4) win over Kohlschreiber to make it all square after Germany's Florian Mayer had earlier sealed a straight-sets 7-6 (7/4), 6-0 win over Juan Monaco.
The final will now be decided by the doubles.
Germany is bidding to win the cup for the first time since 2005, when they beat Argentina, having also captured the title in 1989, 1994 and 1998.
Argentina are playing their seventh final in Dusseldorf having won in 1980, 2002, 2007 and 2010.
The winner will become the first country to capture the team title five times in the tournament's 34-year history.