BEIJING, Oct. 2 (Xinhua) -- Top seeds Victoria Azarenka of Belarus and Novak Djokovic of Serbia both advanced at the cost of German players in the China Open on Tuesday, but followed different paths in their respective matches.
After blitzing Germany's Michael Berrer in the opening set 6-1, Djokovic was pushed to corners unexpectedly in the second by the qualifier player, losing in tiebreak at 7-3.
Djokovic, who is looking to win his third Beijing Open title in four years, got his game back together just in time in the deciding set, finished off the first round match at 6-2.
"Berrer served extremely well. He pushed the second set into a tiebreak where he hasn't missed the first serve and came into the net a couple of times, played some really good points. He deserved to win the second set," the world number two said of his 123rd-ranked opponent.
"He has variety in his game, and he's a big guy and he chips the ball really well. It was definitely unusual because not many players do that, and I had to make the adjustment as the match was going on," the 25-year-old Djokovic added.
World number one Azarenka, however, had a much easy time of it while facing German Sabine Lisicki, winning at 6-4, 6-2 in just one hour and 20 minutes for the third round.
"She's a very dangerous opponent, so that was important to try to be focused right from the beginning to take control, not to let her into the game to start, going for her shots, because she's kind of player that doesn't give much of a rhythm. She likes to take control right from the very beginning," Azarenka said.
"I felt like I played really well in the beginning and took all of my opportunities. I was maintaining from then a very high level."
The Belarussian will be up against Elena Vesnina of Russia for a berth in the quarterfinals.
In another feature match, the odds seemed stacked against China's seventh seed Li Na but she lifted her game in a big way in front of her home crowd, defeating Russian Nadia Petrova 6-1, 6-2 to also move into the third round.
Not only had Petrova just won the Pan Pacific Open title, she had also beaten Li in all six of their career meetings, five of them in straight sets.
It was also the first match of the rivalry in four years as Petrova's last win over Li was at the Stuttgart Open in 2008.
"It was a tough draw to play Li Na at home," Petrova said. "I also played so many matches and spent so many hours on the court in Tokyo, so not only was I a bit fatigued, I had a slight injury in my leg. So today was pretty difficult."
"She played very fast and moved me around, and after a couple of games I started feeling my leg worse and worse, and I couldn't really move to the sides or corners well. I couldn't adjust well and just felt a little bit slow today."
On the other side of the net, however, Li played almost flawlessly, particularly on serve.
"I think that's the charm in playing tennis. Every day you can challenge yourself. You are defeated consecutively, but it doesn't mean you were defeated by her all the time. This is sport. You never know what's gonna happen," said Li, who took just one hour and 19 minutes to finish the lopsided match.
Next up for Li is another unseeded player, but quite familiar -- her fellow Chinese Peng Shuai. The match will guarantee one Chinese in the last eight.
In the day's biggest upset, men's second seed David Ferrer of Spain retired from his opening match against Chinese Taipei's Lu Yen-Hsun while trailing at 5-4 in the first set.
Eighth seed Samantha Stosur from Australia lost to German Julia Goerges 7-6(2), 4-6 and 7-5, becoming another seed casualty following Czech Republic's world No.5 Petra Kvitova's exit the previous day.
Stosur, last year's US Open winner, did created 13 break points but converted on just three of them, while Goerges, the world No. 23, was more efficient having converting three of all her six break points.
Other winners in the women's singles second round include third seed Agnieszka Radwanska of Poland, fifth seed Angelique Kerber of Germany, ninth seed Marion Bartoli of France and former China Open winner Jelena Jankovic of Serbia.
In men's part, third seed Jo-Wilfried Tsonga of France rallied past Uzbekistan's Denis Istomin 4-6, 6-1, 7-6(3). Up against him in the second round will be Russian veteran Nikolay Davydenko.