Shahar Pe'er advanced to the second round in Memphis on Tuesday, defeating Ahsha Rolle 6-2, 6-1 in just over an hour. The 20-year-old Israeli, who dropped one place to No. 18 in the world in this week's rankings, will face Hungarian Melinda Czink (149) in the second round. The key for Pe'er on Tuesday was her serving. Pe'er lost just six of 24 points when getting her first serve in and was only broken once during the encounter. On Monday, Dudi Sela (64) lost in the first round of the men's tournament in Memphis, falling 6-4, 6-2 to Alejandro Falle (84). Defending champion Tommy Haas of Germany won his opening match of the Championships, defeating Diego Hartfield of Argentina 6-3, 6-2 on Monday. Haas, a three-time winner of the tournament and the No. 3 seed, served out the match after gaining his third break of the second set. Hartfield, who defeated Haas two weeks ago in the first round of the Delray Beach International, couldn't overcome a balky backhand, and Haas concentrated on that aspect of Hartfield's game. "It's a different ballgame when you go out there and play in front of a crowd and the nerves play a role. It's not the same as practice," Haas said. "It was a tight match against him [at Delray Beach]. I did have my chances, I just couldn't utilize them. I was still a step too slow, and I made a lot of unforced errors. "[Monday] was different, and it was a great chance to redeem yourself right away." Earlier, second-seeded James Blake withdrew due to a right knee problem that has bothered him for the past few weeks. Blake, who also withdrew from last year's tournament, said he didn't believe he could play a competitive match and plans to rest for the next week or two. Seventh-seeded Jurgen Melzer of Austria was taken to three sets before defeating American John Isner, who was fighting the flu, 6-7 (8), 6-3, 7-6 (4). Top-seeded Andy Roddick, coming off his win on Sunday at San Jose, will play his first match on Wednesday. In the women's Cellular South Cup, fifth-seeded Olga Govortsova of Belarus, defeated Mashona Washington of the United States 6-4, 6-2. Fourth-seeded Lindsay Davenport won 7-5, 6-3 over qualifier Sabine Lisicki of Germany. Like Haas, it was a bit of revenge. Lisicki defeated Davenport 6-1, 7-5 this month when the United States defeated Germany in the first round of the Fed Cup. "It was one of those weird things where playing her in Fed Cup helped me so much," Davenport said. "... This is just one of those luck of the draw things. There were four qualifiers, and I feel like I got the best one out of them." The women's defending champion Venus Williams opens play on Tuesday against Petra Kvitova of the Czech Republic. Meanwhile second-seeded Ivo Karlovic was knocked out in the first round at the ATP Zagreb Indoors on Tuesday, losing 4-6, 7-6 (5), 6-2 to the 209th-ranked Sergiy Stakhovsky of Ukraine. The 21st-ranked Croat served 14 aces and had seven break points before losing. Meanwhile, Maria Sharapova pulled out of the Dubai Championships with a viral infection. The fifth-ranked Sharapova said Tuesday she has been battling a virus for several days and that it has "reached a point where I'm unable to compete." "This is really disappointing to me, but I do intend to come back to Dubai next year and hopefully have a great tournament," she said. Sharapova, who won this year's Australian Open and last week's Qatar Open, was seeded fifth in the tournament and was scheduled to start her campaign Tuesday against Hungary's Agnes Szavay. She was replaced in the main draw by Akiko Morigami of Japan. Sharapova said she was feeling ill even before the Qatar Open. "I have been coughing a lot and feeling tired, but I somehow played through there," she said. "But I don't want to repeat the mistakes I have made in my past, when I tried to play through injuries and sickness and aggravated it." The Dubai Championships offers $1.5 million in prize money and has attracted the six top-ranked players in the world. Sharapova said she would go home and rest for a week, before tournaments in Indian Wells, California, and Miami.