Former champions Venus Williams, Lleyton Hewitt and Maria Sharapova advanced in straight sets, while Tim Henman lost in five, ending any chance of a British man winning the Grand Slam tournament in southwest London for the first time since 1936.

Federer, the world's top-ranked tennis player, resumed at 2-0 up in the third set against Argentina's Juan-Martin Del Potro and completed a 6-2, 7-5, 6-1 victory on Court No. 1 at the All England Club.

"The important match comes now," Federer told reporters. "I just hope I can keep up my good level of play. Safin's a player who can upset anybody on any day."

Federer, of Switzerland, leads Safin, a two-time Grand Slam champion from Russia, 7-2 in career meetings.

Federer, aiming to match Bjorn Borg's five straight Wimbledon titles, extended his record winning streak on grass courts to 50 matches. He has dropped just one set in 13 matches at the tournament, in last year's final against Rafael Nadal.

Safin, the 2000 U.S. Open champion whose best Wimbledon performance was a quarterfinal appearance six years ago, completed a 6-4, 6-2, 7-6 (7-4) victory over Aisam-ul-Haq Qureshi of Pakistan. His last win over Federer came on his way to claiming the Australian Open title in 2005.

"It's a huge challenge," said Safin. "I have nothing to lose because he's the favorite here. I need to play my tennis, stay focused, take my chances."

Henman, a four-time semifinalist, came back from two sets and a break down to tie the match against Feliciano Lopez. The 78th-ranked Spaniard, a quarterfinalist in 2005, broke twice in the final set and sealed the victory with a backhand volley.

"I kept believing I could turn it around and I got back to two sets all," Henman said. "But in the early part of the fifth, he hit a couple of good shots at the right time, and that made it difficult for me."

The 32-year-old Briton vowed to return next year for his 15th Wimbledon. Fred Perry was the last British men's champion at Wimbledon, 71 years ago.

Nadal, the second seed from Spain, beat Austria's Werner Eschauer 6-2, 6-4, 6-1. Nikolay Davydenko of Russia advanced to the third round at Wimbledon for the first time by defeating Australia's Chris Guccione.

Hewitt, the 2002 champion from Australia and seeded 16th this year, beat Italy's Simone Bolelli 6-2, 6-2, 6-1. James Blake of the U.S., seeded ninth, reached the third round with a straight-set win over Romania's Andrei Pavel.

Tommy Haas of Germany, Ivan Ljubicic of Croatia, Dmitry Tursunov of Russia and Jarkko Nieminen of Finland all won in straight sets. Fourth-seeded Novak Djokovic of Serbia and seventh-seeded Tomas Berdych of the Czech Republic won in four sets.

Seeds Tommy Robredo and David Ferrer, both of Spain, and Juan Ignacio Chela of Argentina all lost to lower-ranked opponents.

Mauresmo lost serve in the first game before rebounding to down Austria's Yvonne Meusburger 6-1, 6-2. The defending women's champion from France served eight double-faults.

"It wasn't the best service game today," said Mauresmo, who pulled out of doubles yesterday because of a thigh strain. "I had to focus a bit more to make sure I wasn't in danger."

Sharapova, the 2004 champ from Russia, won 6-0, 6-3 over France's Severine Bremond, a quarterfinalist last year. Williams, a three-time champion who rallied from a set and a break down in the first round, beat Hana Sromova of the Czech Republic 6-2, 6-2.

"I'm constantly looking to go up another level," Williams said. "I feel like I have a good base to just keep playing aggressively on."

Nicole Vaidisova beat Nicole Pratt of Australia 6-3, 6-2 and seeded players Ana Ivanovic, Katarina Srebotnik, Elena Dementieva, Svetlana Kuznetsova and Nadia Petrova all advanced. No. 10 seed Daniela Hantuchova from Slovakia beat Elena Likhovtseva 7-5, 7-6 (7-3).

Michaella Krajicek, whose half-brother Richard won Wimbledon in 1996, dropped one game against Katie O'Brien, the last British woman in the draw. No. 17 seed Tatiana Golovin of France was upset by Austria's Tamira Paszek in three sets.

Men's Seeded Winners— No. 1 Roger Federer, No. 2 Rafael Nadal, No. 4 Novak Djokovic, No. 6 Nikolay Davydenko, No. 7 Tomas Berdych, No. 9 James Blake, No. 10 Marcos Baghdatis, No. 13 Tommy Haas, No. 14 Mikhail Youzhny, No. 15 Ivan Ljubicic, No. 16 Lleyton Hewitt, No. 18 Jarkko Nieminen, No. 19 Jonas Bjorkman, No. 20 Juan Carlos Ferrero, No. 21 Dmitry Tursunov, No. 22 Guillermo Canas, No. 23 David Nalbandian, No. 26 Marat Safin, No. 28 Robin Soderling.

Men's Seeded Losers— No. 11 Tommy Robredo, No. 17 David Ferrer, No. 24 Juan Ignacio Chela, No. 29 Agustin Calleri.

Women's Seeded Winners— No. 2 Maria Sharapova, No. 4 Amelie Mauresmo, No. 5 Svetlana Kuznetsova, No. 6 Ana Ivanovic, No. 8 Anna Chakvetadze, No. 10 Daniela Hantuchova, No. 11 Nadia Petrova, No. 12 Elena Dementieva, No. 14 Nicole Vaidisova, No. 15 Patty Schnyder, No. 19 Katarina Srebotnik, No. 23 Venus Williams, No. 24 Alona Bondarenko, No. 25 Lucie Safarova, No. 26 Ai Sugiyama, No. 28 Mara Santangelo, No. 31 Michaella Krajicek.

Women's Seeded Losers— No. 13 Dinara Safina, No. 17 Tatiana Golovin, No. 21 Tathiana Garbin, No. 29 Francesca Schiavone, No. 32 Martina Muller.

Top Players On Court Tomorrow— No. 1 Federer vs. No. 26 Safin, No. 3 Andy Roddick vs. Fernando Verdasco, No. 9 Blake vs. No. 20 Ferrero; No. 1 Justine Henin vs. Elena Vesnina, No. 7 Serena Williams vs. Milagros Sequera, No. 9 Martina Hingis vs. Laura Granville.