Ivanovic, Henin, Sharapova, Serena advance

MELBOURNE, Jan. 21 (UPI) -- Fourth-seeded Serbian Ana Ivanovic advanced to the quarterfinals of the Australian Open Monday, defeating Denmark's Caroline Wozniacki 6-1, 7-6 (7-2).

The victory sets up a quarterfinal match for Ivanovic against Wimbledon champion and eighth-seeded American Venus Williams, who beat Marta Domachowska of Poland 6-4, 6-4 Monday.

Also going on to the quarterfinals is 29th-ranked Agnieszka Radwanska of Poland, who won in an upset over 14th-seeded Russian Nadia Petrova 1-6, 7-5, 6-0.

Top-seeded Justine Henin, Maria Sharapova and defending champion Serena Williams advanced to the quarterfinals Sunday.

Henin, the tournament's 2004 champion, stretched her winning streak to 32 matches, ousting Taiwan's Su-Wei Hsieh 6-6, 6-2. The reigning French and U.S. Open winner from Belgium next meets the fifth-seeded Sharapova, who downed Elena Dementia 6-2, 6-0 in a match that lasted 62 minutes.

Williams, the No. 7 seed, beat Nicole Vaidisova 6-3-6-4. The American player is on the same side of the draw as Henin and Sharapova, her opponent in last year's final.

Henin said she's expecting a battle with Sharapova.

"I always know to beat her I have to be at my best," Henin said "She's a real fighter. She never gives up."