Top seed Flavia Pennetta was pushed into a decisive third set before sealing her quarter-final place in the Generali Ladies tournament in Linz.

The Italian made an impressive start to her clash with unseeded German Anna-Lena Groenefeld, winning the opening set 6-3, but was broken twice in the second as Groenefeld levelled.

Pennetta hit back with two breaks of her own to race into a 5-1 final-set lead and, though her opponent held serve to delay the inevitable, she completed a 6-3 4-6 6-2 win in one hour and 55 minutes.

She will face Ioana Raluca Olaru, who beat another German, Julia Goerges, also in three sets.

Goerges took the opening set but the Romanian levelled and, after the players had traded breaks, shot down Goerges' serve at the last opportunity to win 3-6 6-2 7-5.

Third seed Yanina Wickmayer will face Italy's Sara Errani in the other clash in the top half of the draw after a three-set win over Romanian youngster Alexandra Dulgheru.

Belgian Wickmayer also had to come from a set down but four breaks in the third set helped her to a 2-6 6-3 6-1 win.

Second seed Agnieszka Radwanska reached the last eight - but was denied a clash with sister Urszula, who lost to Lucie Safarova of the Czech Republic.

Safarova, seeded seventh, wrapped up a routine 6-4 6-4 triumph over the younger of the Polish siblings, but Agnieszka overcame a battling performance by French starlet Alize Cornet.

Cornet saved nine break points but still dropped her serve on five separate occasions en route to a 6-4 7-5 defeat.

Czech Petra Kvitova and fourth-seeded Spaniard Carla Suarez Navarro, who qualified yesterday, complete the last-eight line-up in Austria.