MELBOURNE, Australia -- Serena Williams didn't have to deal with any unexpected distractions Saturday, advancing to the fourth round at the Australian Open.
Williams, who won the title here in 2003, 2005 and 2007, started play on Rod Laver Arena on Day 6 with a 6-1, 6-4 win over No. 41-ranked Peng Shuai of China.
The second-seeded Williams, who gave herself a "D-minus" after her last match, won the last six games of the first set without much trouble but was broken twice early in the second.
She rallied to level at 3-3 before taking a tumble when Peng wrong-footed her with a forehand cross-court winner that set up break point.
The fall seemed to wake up Williams, and she shouted, "Come on!" after whacking an ace two points later and holding serve.
"It was definitely a lot better than my second round. But I'm still trying to work on some things and hoping they'll come together," she said. "I'm feeling a little rusty, for whatever reason."
At least her concentration wasn't challenged like it had been in her doubles win with sister Venus Williams the previous day, when a half-naked streaker ran onto their court.
"I noticed he didn't have underwear on. I thought, 'OK, I must be seeing things," Williams said, chuckling as she reflected on it Saturday. "Then I just thought, 'My eyes, my innocent eyes!"
Also Friday, ethnic violence flared after Novak Djokovic of Serbia beat Bosnian-born American Amer Delic, leaving a woman injured, three men charged with riotous behavior, 30 people ejected by police and broken chairs scattered over the lawn area at Melbourne Park.
Azarenka, 19, won her first career title at Brisbane earlier this month and said she was growing in confidence with her winning streak.
"It's second year in a row but it's fourth round," she said. "We'll see how it goes. I'm sure it'll be a great match."
Dementieva clawed back from 5-2 behind to clinch the opening set in a tiebreak, then eased through the second to chalk up her 13th successive victory this year after winning warm-up tournaments in Auckland and Sydney.
The Bondarenko sisters of Ukraine were ousted within hours of each other, missing out on a fourth-round meeting.
Kuznetsova, the 2004 U.S. Open champion, was broken when serving for the match and needed two more match points in the next game to seal it.
Information from The Associated Press was used in this report.