Dubai, United Arab Emirates (SportsNetwork.com) - Second-seeded former champion Agnieszka Radwanska and defending champ Petra Kvitova were sent packing, while three former world No. 1s, including Caroline Wozniacki and Venus Williams, reached the quarterfinals at the $2 million Dubai Tennis Championships.

Capable Italian Flavia Pennetta knocked out the 2012 champion Radwanska 6-4, 6-1, while nifty Spaniard Carla Suarez Navarro ousted the third-seeded former Wimbledon titlist Kvitova 1-6, 6-4, 7-6 (7-4) on the hardcourts at Dubai Tennis Stadium.

Kvitova defeated Italian Sara Errani in last year's Dubai finale.

Meanwhile, the eighth-seeded 2011 Dubai titlist Wozniacki handled German qualifier Annika Beck 6-4, 6-4 and the 2009 and 2010 Dubai champion and seven- time Grand Slam winner Venus drilled fellow former top-ranked star Ana Ivanovic 6-2, 6-1.

In other second-round action involving seeds, Romanian Sorana Cirstea took out a fourth-seeded Errani 6-2, 5-7, 6-1 and fifth-seeded former world No. 1 Jelena Jankovic doused Czech Lucie Safarova 7-5, 6-4. Jankovic's quarterfinal opponent on Thursday will be current world No. 1 great Serena Williams.

Also on Day 3, France's Alize Cornet took care of Belgian Kirsten Flipkens 6-3, 6-4.

Thursday's other quarters will pit Wozniacki against Cirstea, the wild card Venus versus Pennetta, and Suarez Navarro against Cornet.