Alize Cornet and Sabine Lisicki beaten in Luxembourg Open

Top seed Andrea Petkovic suffered a surprise first-round defeat at the hands of Pauline Parmentier on Tuesday and there were further shocks at the CK Sportcentre in Kockelscheuer a day later.

World number 21 Cornet, the second seed, was beaten 6-2 6-3 by Kiki Bertens in 61 minutes to dash her hopes of securing a second WTA Tour single title this year.

Cornet struggled on serve as she double-faulted on eight occasions and Bertens, ranked 73 in the world, secured six breaks to seal her passage into the quarter-finals.

Bertens immediately put Cornet under pressure as the 22-year-old from the Netherlands went a break up in the first game of the match and, although the Frenchwoman responded to level at 2-2, she went a set down after losing another two of her service games.

Cornet was out of sorts and Bertens took advantage, breaking twice in the second set to lead 4-1 and then taking the first match point that came her way to go through.

It was also a day to forget for third seed Lisicki, as her week was cut short by a 7-5 6-2 defeat against qualifier Denisa Allertova.

The German also struggled on serve, as she clocked up six double faults and only saved one of the seven break points the Czech world number 145 earned as she bowed out.

Sixth seed Roberta Vinci's hopes of winning the title she claimed in 2010 are over after the sixth seed from Italy was beaten 7-5 6-0 by Germany's Annika Beck.

Monica Niculescu was another seed who crashed out in the second round, as Mona Barthel showed character to recover from being blown away in the first set by winning 0-6 7-5 6-3.

Barbora Zahlavova Strycova, seeded four, is now the highest seed remaining in the tournament after seeing off Alison Van Uytvanck 6-4 7-6 (7-1).

Fifth seed Varvara Lepchenko advanced at the expense of Jana Cepelova, who was beaten 6-2 6-2, while there were also wins for Patricia Mayr-Achleitner and Johanna Larsson.