Lleyton Hewitt and Chris Guccione's doubles victory gave Australia a 2-1 lead over Germany on Sunday (AEST) in their Davis Cup World Group play-off to earn a key advantage going into the final day.
Australia is bidding to return to the World Group for the first time since 2007 while Germany must win to stay in the top tier after its opening-round home defeat to Argentina in February.
After Bernard Tomic and Florian Mayer won the first round of singles to make it 1-1, Hewitt and Guccione enjoyed a 6-3, 6-2, 2-6, 7-6 (7-4) victory over Benjamin Becker and Philipp Petzschner.
"I always knew it was going to be tough out there, we expected that from the start," Hewitt said.
"When you can look your partner in the eye in the locker room and know you are going to go into battle together, it is something I have really enjoyed with Chris.
"I feel like I can get the best out of him on the doubles court and it is a good belief to have when we are playing out there together."
In Sunday's final two rubbers, Mayer, ranked 25th in the world, plays teenager Tomic, while Hewitt is due to play 21-year-old Cedrik-Marcel Stebe.
The Germans must win both singles matches to be sure of keeping their World Group status.
Guccione enjoyed his seventh straight doubles win for Australia in the Davis Cup and admitted he was surprised by his own record.
"When I play for my country and pull on the green and gold, it seems to bring out the best in me," said the left-hander ranked 567 in the world in singles, but 133 in doubles.
"I enjoy playing with Lleyton and there is nothing better than playing for my country."
Having clinched the first two sets, the Australian duo allowed their German hosts to establish themselves enough to take the third convincingly at Hamburg's clay-court Rothenbaum stadium.
A tight fourth set was only decided by a tie-breaker, but Hewitt, 31, and the 27-year-old Guccione held on to put their side ahead before Sunday's remaining final matches.
"They compliment each other well, but the Germans were coming back at the boys and fighting hard," said Australia team captain Pat Rafter.
"They were showing a good fighting spirit and we are happy it didn't go to a fifth set."
Elsewhere, the United States stayed alive in its Davis Cup semi-final against champions Spain while four-time runners-up Argentina lost its doubles clash as well as Juan Martin Del Potro against the Czech Republic.
Bob and Mike Bryan beat Marcel Granollers and Marc Lopez 6-3, 3-6, 7-5, 7-5 on the clay courts of Gijon as the US cut the deficit to 2-1 against Spain.
The Olympic and US Open champions secured the crucial point which will mean the tie will be decided on Monday (AEST) with a place in November's final at stake.
Argentina's hopes of making the final suffered a double blow when they slipped 2-1 down to the Czechs and then lost Del Potro through injury.
Tomas Berdych and Radek Stepanek eased past Carlos Berlocq and Eduardo Schwank 6-3, 6-4, 6-3 at a shell-shocked Parque Roca to take their Davis Cup record to 11-1.
World number eight Del Potro withdrew from the reverse singles with a wrist injury.
He will be replaced by world number 45 Berlocq in the clash against US Open semi-finalist Berdych, the sixth-ranked player, before Juan Monaco is scheduled to tackle Stepanek.
In the play-offs, where victory assures a place in the World Group for 2013, the Netherlands stayed in contention against Switzerland in Amsterdam when Robin Haase and Jean-Julien Rojer stunned Roger Federer and Stanislas Wawrinka 6-4, 6-2, 5-7, 6-3.
Federer and Wawrinka, who were doubles gold medallists at the 2008 Olympic Games, had both won their singles on Friday to give the Swiss a 2-0 lead.
Belgium was promoted to the World Group after Olivier Rochus and Ruben Bemelmans beat Sweden's Michael Ryderstedt and Johan Brunstrom 6-4, 4-6, 6-3, 6-2 for an unassailable 3-0 lead in Brussels.
The result means Sweden will not feature in the World Group for the first time since 2000.
Jonathan Erlich and Andy Ram claimed a 5-7, 6-3, 6-3, 6-1 win over Tatsuma Ito and Yuichi Sugita to give Israel a 2-1 lead over Japan in Tokyo.
Elsewhere, Italy leads Chile 2-1 in Naples and Kazakhstan is 2-1 up on Uzbekistan in Almaty.
Canada leads South Africa 2-1 in Montreal while Brazil wrapped up a 3-0 win over two-time champions Russia in Sao Jose do Rio Preto.
AFPTags: sport, tennis, germany, australia First posted September 16, 2012 05:59:36