BIRMINGHAM, England, June 13 (UPI) -- Bethanie Mattek and Marina Erakovic were upset winners Friday in quarterfinal play at the $200,000 DFS Classic tennis tournament in England.
The upsets left 12th-seeded Kateryna Bondarenko the only seeded player to advance to the DFS semifinals. None of the four women in Saturday's semis have won a WTA event.
Mattek knocked off third-seeded Nicole Vaidisova in a 6-3, 6-0 rout. Vaidisova has won just two of her last nine matches.
Erakovic also was a straight-set winner, talking out fifth-seeded Alona Bondarenko, the older sister of Kateryna Bondarenko, 6-4, 7-5.
Kateryna Bondarenko also needed just two sets to advance to the semifinals, winning, 7-6 (7-3), 6-2, over Petra Cetkovska. The fourth quarterfinal Friday saw Yanina Wickmayer eliminate Melanie South, 6-4, 6-3.
Saturday's semifinals pit Kateryna Bondarenko against Erakovic and Wickmayer versus Mattek.