Lleyton Hewitt couldn't stop Australia losing their opening Hopman Cup game, while the United States were also beaten in Group A.
Hewitt wins on return but hosts still humbled by Germany
Defending champions the United States and hosts Australia both suffered shock defeats in their opening matches in the Hopman Cup.
Sabine Lisicki and Nicolas Kiefer steered Germany past the Australians, despite the return to action of Lleyton Hewitt.
The former world number one marked his first match back on court since undergoing hip surgery in August with a hard-fought win over Kiefer.
His 6-7 6-3 6-2 triumph levelled the match after Lisicki had come from a set down to defeat Casey Dellacqua 4-6 6-2 7-5.
Tense finish
The deciding mixed doubles came down to a tense tie-breaker, the German pair coming out on top to clinch victory by a 6-7 6-3 10-5 scoreline.
Despite being unable to stop his country ending up on the losing side, Hewitt was happy enough with his first outing since the Beijing Olympics.
"It's great to be back. It feels good, the hip feels strong," he said.
"I've done everything in my power to get as close to 100 percent for the Australian summer and it's a matter of just trying to come out here now and play a lot of matches."
Champions stunned
Slovakia stunned the USA with a clean sweep to complete a stunning day in Group A of the tournament.
Dominika Cibulkova eased to a 6-2 6-2 triumph over Meghann Shaughnessy in the opening rubber before Dominik Hrbaty sealed the victory.
Having dropped way down the world rankings after struggling with an elbow injury, Hrbaty showed he can still be a match for anyone by prevailing in a final set-tie break to complete a 6-3 4-6 7-6 (7/1) win over James Blake.
Shaughnessy and Blake were then unable to stop their Slovakian opponents completing a 3-0 result in the mixed doubles, going down 6-4 7-6 (7-4).
The winners of the group will play against Russia, France, Italy or Taiwan in the final on Friday.
