Former World No 1 Venus Williams of America fought past ninth-seeded German Mona Barthel 7-6 (4), 6-4 at the 2012 Luxembourg Open on Thursday.

"At 4-0 in the first set, I thought I had the set. Then I started to miss a few shots and she made a few more and the lead was gone," said Venus. "I made sure I stayed positive, though, and I think this helped me get the set in the end.

"I had a lead again in the second, but she was so tough and never gave up. The courts are playing a bit slow and Mona has great defense, so the ball just kept coming back and coming back. She made it so tough but I had to be patient and I'm happy with the result."

The American, who is playing in her first tournament since the U.S. Open, will next face top seeded Roberta Vicni of Italy.

In another match of the day, German Andrea Petkovic edged past third-seeded Jelena Jankovic of Serbia 7-5, 6-0.

Also, Daniela Hantuchova of Slovakia rallied past Kirsten Flipkens of Belgium 6-4, 4-6, 6-2 and Ksenia Pervak of Kazakhstan scored a upset win over sixth-seeded Sorana Cirstea of Romania with 7-6 (4), 6-1 scoreline.