WIMBLEDON, England &

Roger Federer won his 50th straight match on grass, needing only 11 minutes today to complete his 6-2, 7-5, 6-1 victory over 18-year-old Juan Martin del Potro of Argentina to reach the third round at Wimbledon.




The four-time defending champion, who will next face Marat Safin, had led 2-0 in the third set before rain halted play Wednesday. When they resumed, the top-ranked Swiss finished off del Potro, winning three straight games before Del Potro held serve in the sixth game.




"It was done quickly like I was hoping, but I was ready to go five sets in case," said Federer, who broke the Argentine five times and saved the only break point he faced.




The No. 1-seeded Federer, trying to become only the second man in the Open era to win five straight titles at the All England Club, finished with 33 winners and made only 23 errors &

one less than Del Potro.




"Fifty is a great number to achieve," said Federer, who is trying to match Bjorn Borg's streak of Wimbledon titles. "I'm delighted about that but I haven't won the tournament.




Two-time Grand Slam champion Safin beat Aisam-Ul-Haq Qureshi of Pakistan 6-4, 6-2, 7-6 (4) to advance.




"He's always a player who can upset anybody on any day. I hope he's not going to have one of those crazy good days against me," said Federer, who edged Safin 6-4 in the third set at last year's grass-court warmup at Halle, Germany. "I feel like I will have to step it up if I want to beat him."




Federer said skipping this year's Halle tournament has not hurt his play, but he did admit to feeling slightly under the weather.




"I have a bit of throat thing going on, but not much," Federer said.




Three-time champion Venus Williams, wearing white spandex shorts instead of a usual skirt or dress, beat Hana Sromova of the Czech Republic 6-2, 6-2 to reach the third round in the women's draw.




"I really haven't played in shorts before, but my skirt was so big," Williams said. "I think they just made it too big."




Williams, who struggled in the first round Tuesday but eventually beat Russian teen Alla Kudryavtseva in three sets, dominated Sromova with her first serves, winning 100 percent of those points in the first set.




"I think my serve is pretty dynamic right now. It's winning me a lot of points," Williams said.




In the second set, Williams saved break points in the first and seventh games.




French Open finalist Ana Ivanovic also advanced to the third round, beating Meilen Tu of the United States 6-4, 6-3. The sixth-seeded Serb reached the fourth round last year.




Also, No. 8 Anna Chakvetadze defeated Tatiana Poutchek of Belarus 6-2, 6-1, while No. 10 Daniela Hantuchova, No. 12 Elena Dementieva, No. 14 Nicole Vaidisova and No. 15 Patty Schnyder also won.




No. 17 Tatiana Golovin, No. 21 Tathiana Garbin of Italy and No. 29 Francesca Schiavone of Italy lost.




Wayne Arthurs, playing in the final tournament of his 17-year career and at 36 the oldest man in the starting draw, upset No. 11 Tommy Robredo of Spain 6-3, 7-6, (5), 6-3.




No. 9 James Blake advanced by beating Andrei Pavel of Romania 6-4, 6-3, 6-3, and former top-ranked player Juan Carlos Ferrero defeated Gilles Muller of Luxembourg 6-4, 6-4, 6-7 (2), 7-6 (8).




No. 13 Tommy Haas and No. 15 Ivan Ljubicic also won, while No. 17 David Ferrer and No. 24 Juan Ignacio Chela lost.




Second-seeded Rafael Nadal was to play Werner Eschauer of Austria later Thursday, while No. 4-seeded Novak Djokovic and 2002 champion Lleyton Hewitt were also scheduled to play second-round matches.




In women's play, defending champion Amelie Mauresmo was to face Yvonne Meusburger of Austria, with second-seeded Maria Sharapova against Severine Bremond of France.