No.1 seed CoCo Vandeweghe had to play the longest tiebreak of the season to reach the Libéma Open semifinals. The two-time champion defeated her countrywoman Alison Riske 7-6(6), 3-6, 7-6(12) to claim her tenth win of the year.
Vandeweghe saved seven match points in the final set tiebreak but managed to hammer 16 aces and put an end to Riske's 7-match winning streak. The top seed had a set point at 6-5 in the first set that Riske saved with a massive serve and misser other four chances in a row from 6-2 in the followuing tiebreak that she then sealed with an ace and a stunning backhand winner.
A single break was enough to decide the second set. Riske moved ahead to 3-2 after Vandeweghe uncharacteristically netted a forehand and forced the match to a decider with a solid unreturned serve. But the world No.15 in the end claimed the sixth win in a final set tiebreak to 11 defeats and improved to 39-32 her win-loss record in the deciders at WTA level.
Vandeweghe will further pursue her third title here facing in the semifinals No.7 Aleksandra Krunic who beat Russian qualifier Veronika Kudermetova 6-2 6-2 without facing break points. The Serbian, who won 78% of second serve points, has a 5-2 record here.
She's one of the most consistent returners but she lost the only meeting against the American, who owns the fourth highest rate of first serve points this season. Kirsten Flipkens played a match and a half in few hours to seal the second semifinal of the seasob.
She started her day completing the 6-4 6-7(6) 6-1 win over Kiki Bertens in a match interrupted yesterday. Flipkens, the 2013 finalist at the Autotron, had ended ended the Dutchwoman's title defense at the Nürnberger Versicherungscup in three sets ahead of the French Open.
The Belgian came back on court to dismiss No.8 seed Aryna Sabalenka 6-4 6-4 as she won 84% of first serve points and 65% of second serve return points. Antonia Lottner is experiencing another special edition of the tournament.
Just like she did last year, the German qualified for the main draw and in the second-round clash she shocked the second seed Elise Mertens 7-5 6-3. In her second ever WTA quarter-final, she lost to Viktoria Kuzmova. So the Slovak will meet Flipkens for the first time in her career.