WIMBLEDON, England -- Five-time champion Roger Federer outclassed Mario Ancic, the last man to beat him at Wimbledon, in straight sets yesterday to reach the semifinals and extend his grass-court winning streak to 64 matches on the first day of significant rain delays at the All England Club.

Riding his dominant serve and punishing forehand, Federer put on a masterful performance to beat Ancic 6-1, 7-5, 6-4 and move another step closer to becoming the second man in history to win Wimbledon six years in a row.

Federer served 15 aces and finished with three in a row in the final game, including one on a second serve on match point. He won 61 of 71 points on serve, including his last 16, for his 39th straight win at Wimbledon.

"I'm playing great, serving excellent," said Federer, who hasn't dropped a set all tournament. "I really feel like I'm playing as good as I have the last few years. I'm on such a great winning streak on grass. I feel so comfortable on Centre Court. My confidence level is really high."

Federer will next face Marat Safin, who served 18 aces and overcame Feliciano Lopez 3-6, 7-5, 7-6 (1), 6-3 to become the first Russian man to make the Wimbledon semifinals in the 40-year history of the Open era.

In the bottom half of the draw, No. 2 Rafael Nadal edged closer to a third consecutive Wimbledon final against Federer by blowing away Britain's Andy Murray 6-3, 6-2, 6-4.

Nadal, bidding to become the first man to win the French Open and Wimbledon in the same year since Bjorn Borg in 1980, will have to wait an extra day to find out who he'll face in the semifinals.

The quarterfinal between 94th-ranked Rainer Schuettler and No. 145 Arnaud Clement was suspended at one set apiece because of fading light. Schuettler won the first 6-3 and Clement took the second 7-5.

Federer was at his vintage best, holding serve with ease and gliding across the court with cat-like grace. He has reached the semifinals for the 17th consecutive time at a Grand Slam event.

Safin, a former top-ranked player who won the 2000 U.S. Open and 2005 Australian Open, has slipped steadily in the rankings over the past three years and came into the tournament at No. 75.

The Russian got off to a rocky start against the left-handed Lopez, and was down 5-2 in the first set when play was suspended by rain. Even though he ended up losing the set, Safin stepped up his game after the break and took command. Lopez double-faulted on set point in the third-set tiebreaker and served his sixth double-fault on match point.

Venus and Serena Williams, who between them have won six of the past eight Wimbledon women's titles, are one round away from a third women's title matchup and seventh Grand Slam championship showdown.

Next up for two-time champion Serena in today's semifinals is Zheng Jie, who became the first Chinese player to reach the semifinals of a Grand Slam. Defending champion and four-time winner Venus will next face No. 5 Elena Dementieva.