Porsche Grand Prix, Filderstadt
Daniela Hantuchova will face top seed Kim Clijsters in the last 16 after edging past Lisa Raymond on Tuesday.
The world number 13 saved two break points at 3-3 in the opening set before going on to beat the American 6-3 6-4 and set up a repeat of last year's final.
Second seed Justine Henin-Hardenne later beat Conchita Martinez 6-0 7-6 to become the first player to reach the quarter-finals.
"I was very pleased with the way I played today because Lisa is very tough to play indoors," said Hantuchova.
"I think what made the difference was that I just kept fighting even though I was down on my service games.
"But there are still many things that I have to improve and against Kim I will have to step up and raise my level.
"For a second round it's pretty tough to play the opponent I had in the final last year but I'm looking forward to the match."
Mary Pierce thrashed Zimbabwean qualifier Cara Black 6-2 6-0 and will now face with fourth seed Jennifer Capriati.
Jelena Dokic's disappointing season continued with a 7-5 6-0 defeat to Bulgaria's Magdalena Maleeva.
Tashkent Open
Play got underway a day late after persistent rain on Monday, with the leading names making swift progress.
Top seed Petra Mandula of Hungary beat Uzbekistan's Akugul Amanmuradova 6-4 7-6, while second seed Emmanuelle Gagliardi saw of Switzerland saw off Anastasia Rodionova 6-2 6-4.
And fourth seed Virginia Ruano Pascual then eased past Adriana Barna of Germany 6-2 6-3.
Angelique Widjaja, the seventh seed, defeated Claudine Schaul of Luxembourg 6-7 6-4 7-6, and eighth seed Jelena Kostanic thrashed Slovakia's Eva Fislova 6-1 6-2.