LINZ, Austria -- Top-seeded Angelique Kerber defeated Patricia Mayr-Achleitner of Austria 6-3, 6-1 in the quarterfinals of the Generali Ladies on Friday to secure the final spot in the season-ending WTA Championships.
"Qualifying for Istanbul is a great achievement," Kerber said. "It's the reward for my consistency though I've had my ups and downs and a couple of injuries this year."
The 10th-ranked German next plays fourth-seeded Carla Suarez Navarro of Spain, while two-time former champion Ana Ivanovic will take on Stefanie Voegele of Switzerland. The 58th-ranked Voegere reached the last four by upsetting second-seeded Sloane Stephens 6-7 (3), 6-4, 7-5.
Kerber saved a break point while trailing Mayr-Achleitner 3-2 in the opening set. She then won nine straight games to lead 6-3, 5-0 before closing out the victory on her first match point.
"I was a bit nervous at the start and Patricia played really well," Kerber said. "Then I settled and felt more relaxed."
Ivanovic defeated seventh-seeded Dominika Cibulkova of Slovakia 6-2, 6-4. The third-seeded Serb, who won the event in 2008 and '10, was 3-0 down in the second set before reeling off four straight games.
The former top-ranked Ivanovic is yet to reach a final this season.
Earlier, Voegele won the last five games to complete her comeback against the 12th-ranked Stephens.
"To come back from 2-5 in the final set is incredible," said Voegele, who reached her third semifinal of the season. "I told myself to keep on fighting and I am proud that I was able to win."
Suarez Navarro beat fifth-seeded Kirsten Flipkens of Belgium 6-1, 6-3 to reach her fourth semifinal of the season and first on hardcourt. Suarez Navarro won the first eight points of the match and held serve throughout.