World number one Lindsay Davenport [Images] turned in a stuttering performance as she struggled to a 2-6, 6-2, 6-2 victory over Czech Michaela Pastikova in the second round of the Australian Open on Thursday.

The top seed and former champion looked in trouble when she dropped the opening set to an inspired Pastikova, but an early break in the second set lifted the American's confidence and she eased to victory in one hour, 22 minutes.

"I knew I wasn't playing my best today," Davenport said. "But she played really well.

"I just wasn't ready to be at my best at the very beginning, and it definitely cost me against someone who came out playing very well, very aggressive and kind of caught me on my back foot."

The 24-year-old Pastikova, playing in her first Grand Slam event, stunned Davenport in the first set, breaking three times to surge ahead.

However, once Davenport had broken serve in the second set, she was always in command.

"I tried to buckle down after I lost the first set and concentrate more in the short-term than in the long-term," Davenport said.

"In both the second and third sets, I got off to good leads, and that really helped carry me through both sets.

Davenport had thought about retiring last year after being plagued by injuries but decided to play on after finishing the season ranked number one in the world.

The 28-year-old California said she was concerned about the lack of Americans coming through the rankings and predicted things would only get harder in the years to come.

Russia [Images], with four players in the top six, have replaced the U.S. as the new power in women's tennis and Davenport said China was also starting to emerge.

"I think that China's come a long way in producing a bunch of players. While there's no-one in the top 10 or top 20 yet, I mean, all of a sudden they've got I think five or six legitimate players in the top at least hundred that are improving rapidly," she said.

"It seems like tennis has kind of caught on in that part of the world, as well.

"I've heard that because of the Olympics [Images] next time around, they've put a lot of money into it and are trying to develop these players. It seems to have really helped.

"I mean, five years ago, I don't remember any player from China. Now we've got, five or six good ones."

• Complete tennis coverage
• All you want to know about Sania Mirza