Tsvetana Pironkova celebrates winning her first-ever WTA title at the Sydney International.
Mark Nolan/Getty Images

SYDNEY (AP) -- Bulgarian qualifier Tsvetana Pironkova beat fifth-seeded Angelique Kerber of Germany 6-4, 6-4 on Friday to win her first WTA title at the Sydney International.

Pironkova, who was ranked outside the top 100 despite reaching the Wimbledon semifinals in 2010, beat three top 10 players in Sydney, 2012 French Open finalist Sara Errani, 2011 Wimbledon champion Petra Kvitova and Kerber.

Unseeded Lu Yen-hsun of Taiwan stopped David Ferrer's bid for a fifth singles title at the Heineken Open in Auckland, New Zealand, with a 6-4, 7-6 (4) win in his first-ever semifinal at ATP level.

Lu moved into a final against third-seeded John Isner, who rallied from a set and a break down to beat unseeded Roberto Bautista Agut 3-6, 7-6 (2), 6-4.

Ferrer won the Auckland title in 2007 and in each of the last three years but dropped serve twice and made 20 unforced errors in the first set.

''I know he's a tough guy and I tried to play my best tennis and fortunately I did it,'' Lu said. ''He's not playing bad, I just played unbelievable.''

Ferrer is seeded No. 3 for the Australian Open.

In a preview of their first-round match at the Australian Open, Klara Zakopalova of the Czech Republic beat 2011 U.S. Open champion Sam Stosur 6-3, 6-2 in the semifinals of the WTA event in Hobart.

Zakopalova will next play Garbine Muguruza, who beat Estrella Cabeza Candela 6-0, 6-1 in a semifinal between two Spanish qualifiers.

At the Kooyong Classic exhibition tournament in Melbourne, Richard Gasquet had a 7-6 (3), 1-0 win over Gilles Simon when his fellow Frenchman retired with an injured right ankle.

Gasquet was due to meet Tomas Berdych in Saturday's final but withdrew later Friday due to general soreness. Berdych will play Kei Nishikori in the final.

Copyright 2014 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

SI Apps
We've Got Apps Too
Get expert analysis, unrivaled access, and the award-winning storytelling only SI can provide - from Peter King, Tom Verducci, Lee Jenkins, Seth Davis, and more - delivered straight to you, along with up-to-the-minute news and live scores.