WIMBLEDON, England — Erratic but overpowering, Venus Williams beat Sabine Appelmans 6-4, 6-4 Monday to reach the quarterfinals at Wimbledon for the third year in a row.
Williams' opponent Tuesday will be top-seeded Martina Hingis, who defeated No. 11 Anke Huber 6-1, 6-2.
Unseeded American Lisa Raymond advanced to her first Grand Slam quarterfinal by beating Olga Barabanschikova 6-4, 6-2. Another American, Lilia Osterloh, lost in the fourth round to Magui Serna 7-6 (1), 6-3.
Qualifier Vladimir Voltchkov of Belarus became the first men's quarterfinalist, sweeping Wayne Ferreira 6-3, 6-4, 7-6 (0). Voltchkov is ranked No. 237.
On the warmest, sunniest day of the tournament, Williams had trouble finishing off Appelmans, who erased three match points serving at 1-5, 0-40 in the second set. The fifth-seeded Williams then double-faulted twice to lose her serve for the only time before closing out the match two games later.
"I just made some errors," she said. "There were a lot of easy shots I missed. I don't usually do that."
The 6-foot-1 Williams took advantage of her height by coming to the net often, and her booming groundstrokes into the corners kept Appelmans on the run. But Williams, playing in only her fourth tournament after a six-month layoff because of tendinitis in both wrists, prolonged the match with sloppy errors that had her shaking her head in dismay.
"It's annoying," she said. "I can raise the level of my game. There's no way these girls should be competing against me like that."
Her father, Richard, attending Wimbledon for the first time, watched with photographers in the first row behind the baseline on court two. On Tuesday, his daughter will try for her first berth in the Wimbledon semifinals.
Williams said she's not afraid of Hingis, who is ranked No. 1.
"So what?" Williams said. "I've played Martina thousands of times."
Raymond's victory represented a breakthrough for the 26-year-old Pennsylvanian, a former NCAA champion at Florida. She had lost in the fourth round at Wimbledon three times previously.
Raymond will next play the winner of the fourth-round match between Williams' sister, Serena, and Tamarine Tanasugarn.
In keeping with tradition, there were no matches on the middle Sunday. Top-seeded Pete Sampras and No. 10 Mark Philippoussis, among others, welcomed the rest.
Sampras is hampered by acute tendinitis above the ankle in his left leg.
"It'll probably continue to be sore," the six-time Wimbledon champion said after beating Justin Gimelstob on Saturday. "I'm here to complete the tournament, win or lose."
Philippoussis survived a five-hour marathon Saturday against Sjeng Schalken, winning the longest fifth set at Wimbledon in the open era, 20-18.
"I feel I've just been punched to death for five hours," Philippoussis said.
Only six seeded men and seven women survived three rounds.