Vandeweghe stuns Halep

Vandeweghe, who won 6-4, 6-1 in an hour and 14 minutes, fired five aces and 19 winners to exert her dominance in the claycourt event despite previously stating her dislike for the surface.

US Open semifinalist 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 in two hours and 16 minutes.

Germany’s former world No. 1 Angelique Kerber had to quit with a right thigh injury Thursday and was swiftly followed by second seeded Wimbledon champion Garbine Muguruza who called it quits with back pain.

The limping Kerber handed over a 6-0, 2-0 second-round win to Anett Kontaveit of Estonia.

Barely an hour later, Spain’s Muguruza was unable to go on due to lower back pain after dropping the opening set of her first match of the week 7-5 to Russian Anastasia Pavlyuchenkova.

In all, three of the day’s seven matches ended in retirements — earlier third seeded Elina Svitolina of Ukraine was 2-6, 6-1, 3-2 ahead of Marketa Vondrousova when the Czech qualifier quit with right thigh trouble.