(Reuters) - American CoCo Vandeweghe shocked world number one Simona Halep 6-4 6-1 on Friday to move into the semi-finals of the Porsche Tennis Grand Prix in Stuttgart.
Vandeweghe fired five aces and 19 winners to exert her dominance in the claycourt event despite previously stating her dislike for the surface.
U.S. Open semi-finalist Vandeweghe raced to a 5-4 lead in the opening set on the back of her strong service game. The 26-year-old then sealed a decisive break to clinch the first set and gain the upper hand in the contest.
Despite stepping up her attack, Romania's Halep struggled to find a way past her opponent who cruised through the second set to reach the last four of a claycourt event for the first time.
Vandeweghe next takes on sixth seed Caroline Garcia who later overcame Ukraine's Elina Svitolina 6-7(4) 6-4 6-2.
Anett Kontaveit emerged victorious 7-5 6-7(6) 6-4 against Anastasia Pavlyuchenkova and the Estonian next takes on fifth seed Karolina Pliskova who came from behind to beat a determined Jelena Ostapenko 5-7 7-5 6-4 in the evening session.
(Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Christian Radnedge and Pritha Sarkar)