Berlin (Germany), Jun 23 (IANS): China's Xu Yifan and Anna Danilina of Kazakhstan were defeated by Czech duo Katerina Siniakova and Marketa Vondrousova 3-6, 7-5, 7-10 in the quarterfinals of the WTA500 Berlin Open at the Steffi Graf Stadium.

Xu and Danilina had an ideal start on Thursday, leading the first set 3-0 before sealing a 6-3 victory, but Siniakova and Vondrousova came back strongly in the second set to break twice to win 7-5. After a 4-4 tie in the decider, Xu and Danilina lost three straight points to eventually fall 10-7, reports Xinhua.

"I did not score some key points and lost a match point in the second set, which was the turning point. Momentum was not on our side thereafter," said 34-year-old Xu.

"I had some injuries this season, so the most important thing for me is to keep fit and stand on the court for the coming matches," added Xu. "I want to return to the world top 10 [in the doubles], but that seems not to be under my control. I will keep training every day and try my best to play well in the following grass tournaments."

Siniakova and Vondrousova will face Desirae Krawczyk of the United States and Demi Schuurs of the Netherlands in the semifinal, after the latter pair outplayed Daria Kasatkina of Russia and Germany's Sabine Lisicki to win 6-3, 6-4.