Updated

Brisbane, Australia (SportsNetwork.com) - Andrea Petkovic and Angelique Kerber won singles matches Saturday to give Germany a commanding lead against Australia in the Fed Cup semifinals.

Petkovic defeated former U.S. Open champion Samantha Stosur, 6-1, 7-6 (9-7), and Kerber made short work of Casey Dellacqua in a 6-1, 6-0 rout for a 2-0 advantage in the best-of-five tie. The Germans need just one point on Sunday to wrap up a berth in the final.

"I saw two great matches and I was very proud of the performance of my two girls," said German captain Barbara Rittner. "There are still three points to go and tomorrow is a new day. I think the matches were closer than they look."

On Sunday, reverse singles will pit the 19th-ranked Stosur against Kerber and Petkovic versus Dellacqua. The doubles match has a German tandem of Julia Goerges and Anna-Lena Groenefeld taking on an Aussie duo of Dellacqua and Ashleigh Barty.

Petkovic needed just 37 minutes to win the first set Saturday. She broke serve to start the match, but Stosur broke right back. It was all Petkovic from there with three more breaks of serve.

Stosur broke for a 2-1 lead in the second set and was serving for the set at 5-4 when Petkovic broke to even it. The German opened a 6-3 lead in the tiebreaker, but Stosur won the next three points to keep it going. She saved another match point soon after, but could not stave off a fifth match point.

"I had put myself in a good position in the second set so it was disappointing to lose it," said Stosur.

Kerber then had no trouble in the second match Saturday, polishing off Dellacqua in a mere 51 minutes. Kerber converted 6-of-10 break points and had her serve broken just once.

"I played very good," said Kerber. "Of course it is easier to go on the court when your country is leading 1-0, but I knew I had to play very good because Casey is playing very good at home."

Australia is 8-4 all-time against Germany, including a win in their last meeting in a World Group Playoff in 2012. The two nations first met in 1966.

The winner will meet the Czech Republic-Italy victor in the Fed Cup final in November.