Tokyo:Top-seeded Venus Williams overcame some early errors on Thursday to defeat Alicia Molik and advance to the semifinals of the Japan Open.
Williams downed Molik 7-6 (4), 6-3 to set up a semifinal showdown with Denmark's Caroline Wozniacki, who defeated Klara Zakopalova of the Czech Republic 6-3, 2-6, 7-6 (3).
"I was having some problems with my errors which was frustrating," said Williams. "She played well and had the skills to win the match."
Williams, No 8 in the WTA rankings, struggled with her serve in the first set, double faulting five times, but took control midway through the second set as Molik made some costly errors of her own.
"There were times when I was good and times when I wasn't," said Williams. "Now I just have to focus on the semifinals."
Williams went ahead 4-3 when Molik double faulted in the seventh game of the second set and then held serve to go up 5-3.
She won the match with a crosscourt forehand off Molik's serve.
Williams is playing in the $175,000 tournament for the first time and is bidding for her fourth title of the season. She won the Korea Open on Sunday.
In the US$832,000 men's tournament, Croatia's Ivo Karlovic, seeded seventh, ground out a 7-6 (6), 6-7 (8), 7-6 (8) win over ninth-seeded Lee Hyung-taik of South Korea to advance to the quarterfinals.
Australian Lleyton Hewitt, seeded fourth, downed Spain's Ivan Navarro 7-5, 6-3.
Fernando Verdasco of Spain defeated Sweden's Thomas Johansson 7-6 (4), 5-7, 6-3.