Luxembourg - Annika Beck of Germany has advanced to the quarter-finals of the Luxembourg Open with a 6-2, 6-2 win over Patricia Mayr-Achleitner of Austria on Thursday.
Mayr-Achleitner struggled with her serve throughout, hitting four double-faults and winning less than half of the points on her first serve.
The 60th-ranked Beck beat sixth-seeded Roberta Vinci of Italy in the previous round.
Kiki Bertens of the Netherlands could not follow up her win over second-seeded Alize Cornet, however, slumping to a 6-3, 6-0 loss to Mona Barthel of Germany.
Barthel hit seven aces and saved six of the seven break points she faced to set up a quarterfinal match against either fourth-seeded Barbora Zahlavova Strycova or Johanna Larsson.
Zahlavova Strycova is the highest seeded player remaining in the draw.
Results on Thursday from the WTA Luxembourg Open (x denotes seeding):
Denisa Allertov (CZE) bt Varvara Lepchenko (USA x5) 4-6, 6-3, 7-5
Annika Beck (GER) bt Patricia Mayr-Achleitner (AUT) 6-2, 6-2
Barbora Zhlavov Strcov (CZE x4) bt Johanna Larsson (SWE) 6-0, 6-2
Mona Barthel (GER) bt Kiki Bertens (NED) 6-3, 6-0