Tokyo, Japan (AHN) - Venus Williams advanced to the semifinal round of the Japan Open on Thursday with a decisive 7-6 (4), 6-3 win over Australia's Alicia Molik.

Williams, the tournament's top seed, utilized her efficient groundstrokes and blazing speed to send Molik packing in just over 90 minutes at Ariake Colosseum.

"I was having some problems with my errors, which was frustrating," Williams said. "She played well and had the skills to win the match."

Williams committed five double faults but took control of the match midway through the second set as Molik made several costly errors of her own.

"There were times when I was good and times when I wasn't," Williams said. "Now I just have to focus on the semifinals."

Williams, who won Korea Open on Sunday, is seeking her fourth title of the year. Williams took the lead at 4-3 when Molik double faulted in the seventh game of the second set and before holding serve to go up 5-3.

Williams finished off Molik when she blasted a cross-court forehand for a winner off Molik's serve.

France's Virginie Razzano stopped fellow Frenchwoman Camille Pin 6-2, 6-2, while eighth-seeded Italian, Flavia Pennetta beat second-seeded Sania Mirza of India 6-4, 6-4 in two other quarterfinal matches.

On the men's side, Spaniard David Ferrer, the tournament's top-seed, beat Vincent Spadea of the United States 6-1, 7-6 (0) while Croatian, Ivo Karlovic, managed a 7-6 (6), 6-7 (8), 7-6 (8) win over ninth-seeded Lee Hyung-taik of South Korea to advance to the quarterfinal round.

Australia's Lleyton Hewitt, seeded fourth, stopped van Navarro of Spain 7-5, 6-3, while another Spaniard, Fernando Verdasco, defeated Thomas Johansson of Sweden 7-6 (4), 5-7, 6-3.