Samantha Stosur gave Australia a 1-0 lead over Germany in their Fed Cup World Group playoff by beating Angelique Kerber in straight sets on Saturday.
The fifth-ranked Stosur defeated her German rival 7-6 (1), 6-4 in one hour 41 minutes on the indoor hardcourt.
Kerber had a career high ranking of No. 14 going into the weekend and Germany has three players in the top 20.
The 16th-ranked Julia Goerges was hoping to level the tie against Jarmila Gajdosova, ranked 34 places below her, in Saturday's second singles match.
The best of five series will be decided Sunday with two reverse singles and a doubles match at the Porsche Arena.
Australia has seven wins from 11 previous meetings between the countries.