Fresh off winning a second consecutive Australian Open, top-ranked Victoria Azarenka breezed into the third round of the Qatar Open with a 6-2, 6-3 victory over Romina Oprandi.

The defending champion was joined by fourth-ranked Agnieszka Radwanska and former No 1 Caroline Wozniacki. Radwanska beat Australian qualifier Anastasia Rodionova 6-3, 6-2, and Wozniacki downed Sorana Cirstea of Romania 7-6 (7), 6-0.

Sloane Stephens, the 16th-seeded American who upset Serena Williams in the Australian Open quarterfinals, was beaten 4-6, 7-6 (5), 7-6 (5) by Klara Zakopalova of the Czech Republic.

"Today was a tough match," Stephens said. "The conditions were tough but Klara played well. Now I just need to regroup and keep working on my game and get ready for Dubai."

Azarenka will retain her top ranking if she reaches the final and Williams fails to reach the semi-finals. She made a nervous start, dropping serve to fall 2-0 behind. But the Belarussian recovered to break three times and win the first set. Azarenka jumped out to 3-0 in the second set and wasn't caught.

"Well, it wasn't easy for sure, but you never want to take this as an excuse because it's the same for both players," Azarenka said of the windy conditions.

"I think she's a very tricky opponent, especially in those conditions. You know, when you haven't played a match it can be a little bit tricky as well," she said. "I'm glad I could turn it around. I felt like it was a little bit of a slow start for me. I started to go too much for my shots at the beginning. Then I started to be more patient, work more the points. Got me more into the game and started to play much better."

Radwanska had little trouble with the 131st-ranked Rodionova, breaking to go up 3-1 on the way to winning the first set. The second set was even more one-sided, with the Pole breaking twice on the way to victory.

"Well, I was really feeling pretty good out there," Radwanska said. "But for sure the conditions today was not easy at all. It was really windy and the wind changed every couple of minutes.

"It was very tricky, but I'm just very happy that I could play my really good tennis in the important moments and I finished this match in two sets."

Radwanska has started the season well, winning in Sydney and Auckland and reaching the quarterfinals of the Australian Open. Having reached the Wimbledon final last year, she feels ready to challenge for the No 1 ranking.

"It's always a little bit of pressure but I think this is the dream for everyone to be in the final of a Grand Slam and, of course, to be No. 1 in the world," she said. "I was really close to that last year, and definitely I'm going to try to do it this year.

"I hope I can have some more opportunity to win the major final. But of course it's hard, especially being top five. It means that we have to play a lot of good tournaments, not one or two tournaments. You have to play on a good level pretty much the whole year and try to be very consistent. That's what I'm trying to do."

Several seeded players crashed out. They included Stephens and No. 17 Lucie Safarova of the Czech Republic, who was beaten 6-4, 6-2 by Christina McHale of the United States. Urszula Radwanska, the sister of Agnieszka, upset 15th-seeded Roberta Vinci of Italy 6-2, 5-7, 6-0.

- AP