Australia came into the World Group semifinal tie with an 8-4 lead in its series with Germany and home court advantage, but the Germans were in control of this one from the outset.
Andrea Petkovic's 61 76(7) triumph over Stosur was a continuation of her recent superb form that saw her capture her biggest WTA title in Charleston two weeks ago. Kerber followed that up with a 51-minute, 60 61 rout of Casey Dellacqua that gave Germany a 2-0 lead after Saturday's play.
The next day, Kerber sought her first win in three tries against Stosur, a series that began with a win for Stosur in the 2011 US Open semifinals en route to her lone Grand Slam title.
But this time Kerber pulled out a 46 60 64 victory, with the key stat being her 23 unforced errors compared to 54 for Stosur. That improved her to 5-0 in Fed Cup hardcourt matches, and in the process gave Germany an insurmountable 3-0 lead. Remarkably, Stosur came into this tie with 33 Fed Cup match wins under her belt, including a 25-3 record outdoors, but the Germans were able to get the best of the Brisbane native twice.
The tie finished with a 3-1 score, with Australia getting on the board when three-time Grand Slam runners-up Ashleigh Barty and Dellacqua edged Julia Goerges and Anna-Lena Groenefeld, 62 67(5) 102. Germany also was a 3-1 winner in its first round rubber against the Czech Republic in February.
Germany will go on the road when it takes on the Czech Republic for the title from November 8-9. It will be seeking its third Fed Cup title, having previously won it with the help of Steffi Graf in 1987 and 1992, the last year it reached the final.