Doha - Fourth-seeded Agnieszka Radwanska brushed aside Flavia Pennetta 6-1, 6-1 on Wednesday to set up a quarter-final with Venus Williams in the Qatar Open.
Radwanska, who had lost both their previous meetings, including the Indian Wells final in March last year, dropped just 11 points in her seven service games.
The Pole broke her opponent's serve five times in a match that lasted just 49 minutes.
Radwanska will play Williams on Thursday.
Top-seeded Petra Kvitova will take on third-seeded Caroline Wozniacki for a place in the semi-finals after both had shortened matches.
Kvitova had a 6-3, 1-1 lead against Jelena Jankovic when her opponent retired, while Wozniacki was leading 6-1, 3-0 when Romanian qualifier Alexandra Dulgheru withdrew.
Lucie Safarova also advanced by beating fifth-seeded Ekaterina Makarova 6-2, 6-7 (5), 6-3.