LONDON (Reuters) - Nicole Vaidisova was blasted out of the Edgbaston WTA tournament by American Bethanie Mattek on Friday, losing their quarter-final 6-3 6-0.

The third seed and former world number seven was bundled out in 52 minutes as her poor run of form continued. Before arriving in Birmingham for the Wimbledon warm-up the Czech had lost in the first round of her previous five tournaments.

Fifth seed Alona Bondarenko from the Ukraine also fell, losing 6-4 7-5 to New Zealand's Marina Erakovic, meaning only one seed has reached the semi-finals.

That honour went to Bondarenko's sister Kateryna, who beat Petra Cetkovska of the Czech Republic 7-6 6-2.

Briton Melanie South's run came to an end when she lost 6-4 6-3 to Yanina Wickmayer of Belgium.

"My game plan was just to make her play every point," world number 81 Mattek said on the tournament's Web site (www.lta.org.uk). "I knew she hadn't had a lot of wins recently and I wanted to stop her taking the initiative out there."

Mattek, who has never won a Tour title, faces Wickmayer in the semi-finals with 12th seed Bondarenko up against Croatia-born Erakovic.

This year's tournament has been hit hard by withdrawals including Maria Sharapova and Jelena Jankovic.

(Reporting by Martyn Herman, editing by Alan Baldwin)