DOHA, Qatar (AP) -- Top-seeded Li Na, playing her first match since winning the Australian Open last month, beat Magdalena Rybarikova of Slovakia 6-1, 5-7, 6-2 in the second round at the Qatar Open on Wednesday.

Third-seeded Petra Kvitova of the Czech Republic struggled to outlast Venus Williams of the United States 6-2, 2-6, 7-6 (7) in a match lasting 2 hours, 32 minutes.

Also, second-seeded Agnieszka Radwanska of Poland defeated Sorana Cirstea of Romania 7-5, 6-0.

Copyright 2014 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

SI Apps
We've Got Apps Too
Get expert analysis, unrivaled access, and the award-winning storytelling only SI can provide - from Peter King, Tom Verducci, Lee Jenkins, Seth Davis, and more - delivered straight to you, along with up-to-the-minute news and live scores.