Kim Clijsters won her first match since her US Open triumph, crushing Klara Koukalova 6-3 6-0 in the second round of the Luxembourg Open.
Clijsters was untroubled throughout
The Belgian showed no signs of rustiness when winning the last nine games against her Czech opponent.
Top seed Clijsters will play Francesca Schiavone in the quarter-finals after the Italian's second round opponent, Virginie Razzano retired with injury.
Slovakia's Daniela Hantuchova beat Anna Chakvetadze 6-4 6-1.
Hantuchova, the fifth seed, called for the trainer just three games into her second-round match against the Russian 18-year-old.
Hantuchova will play either fourth seed Nathalie Dechy or Madagascar's Dally Randriantefy, who brushed aside American Meilen Tu 6-1 6-2 in the first round.
In other first-round matches, Italy's Roberta Vinci edged out Michaella Krajicek of the Netherlands 7-6 6-4, qualifier Jarmila Gajdosova of Slovakia beat Slovenia's Katarina Srebotnik 7-6 6-4, and Anna-Lena Groenefeld of Germany defeated Greece's Eleni Daniilidou 6-4 6-4.