Safina is the world number one
Top-seeded Russian Dinara Safina will face Slovakia's Daniela Hantuchova in the quarter-final of the Ordina Open.
The pair meet in the Netherlands after Safina beat Yaroslava Shvedova 6-3 6-3 while Hantuchova beat Ukraine's Kateryna Bondarenko 2-6 6-2 6-1.
In the other quarter-final fifth-seeded Francesca Schiavone of Italy will meet Olga Govortsova of Belarus.
Number three seed Flavia Pennetta faces Tamarine Tanasugarn while Kristina Barrois takes on Yanina Wickmayer.
"I made a slow start and had to focus on my own game, when I managed that I turned it around," said Hantuchova.
In the men's draw defending champion David Ferrer reached the quarter-finals with a 6-4 6-3 win over Oscar Hernandez.
Ferrer's next opponent will be fellow Spaniard Ivan Navarro.
Elsewhere German qualifier Benjamin Becker will play 2004 champion Michael Llodra in the last eight.
Fourth-seeded Rainer Schuettler next plays seventh-seeded Jeremy Chardy of France while Holland's Raemon Sluiter meets Dudi Sela of Israel.
Sela advanced after his opponent Marcos Baghdatis retired citing a knee injury at 4-3 in the first set.