Eighth-seeded Vasek Pospisil of Vancouver defeated Germay's Jan-Lenard Struff 6-4, 6-2 to reach the quarter-finals of the Topshelf Open, a grass-court warm-up ahead of Wimbledon, in ‘s-Hertogenbosch, Netherlands, on Wednesday.

Second-seeded Spaniard Fernando Verdasco beat wild-card entry Jesse Huta Galung 7-5, 6-3 to reach the quarters.

Verdasco earned the first break of his match in the 12th game of the first set when Huta Galung knocked an easy backhand out.

In the second set, Verdasco broke the Dutch home favourite in the fourth game with a forehand passing shot. Verdasco saved a break point in his final service game before serving out the match.

Verdasco will next play Jurgen Melzer after the Austrian beat Lukas Lacko 5-7, 6-3, 6-3. Benjamin Becker of Germany and Joao Sousa of Portugal also advanced, along with seventh-seeded Frenchman Nicolas Mahut.

Three players retired from matches in the women's draw, with French Open finalist and top-seeded Simona Halep pulling out due a sore right shoulder when she was leading 5-7, 3-2 against Annika Beck of Germany. Fourth-seeded Carla Suarez Navarro of Spain retired when China's Zheng Jie was leading 7-5, 0-1; and Vania King left the court in the third set against fellow American Coco Vandeweghe, who was leading 6-7 (6), 6-0, 2-1.

In other women's matches, Urkraine's Elina Svitolina had a 7-6 (4), 6-4 upset win over No. 6-seeded Kirsten Flipkens and eighth-seeded Klara Koukalova defeated Mona Barthel of Germany 6-2, 7-6 (6).