Melbourne, Australia - Serena Williams cautiously walked onto the court, and tried to keep the points short to avoid irritating her injured right ankle as she advanced to the third round at the Australian Open.

Summoning all her experience from 15 major titles, including the final two of the last season, Williams lifted her tempo on the biggest points - winning an 18-minute game to open the second set, finally cashing in on her fourth break chance. Nineteen minutes later, she finished off a 6-2, 6-0 win over No. 112-ranked Garine Muguruza of Spain.

Apart from a swollen lip from hitting herself in the face with her racket in the sixth game, she emerged unscathed.

"It feels better," Williams said of her ankle. Before the match "I was just doing everything you can do - icing to massage. I woke up this morning and thought ... "Oh my God, it feels good. "

"I'll keep my fingers crossed."

Despite the injury concerns, Williams said she would be playing doubles later with sister Venus, and will play her next singles match against Japan's Ayumi Morita on Saturday.

Defending champion Victoria Azarenka practically danced into Rod Laver Arena for the match before Willliams' victory, and said she's starting to find some rhythm after beating Eleni Daniilidou 6-1, 6-0 in 55 minutes.

The No. 94-ranked Daniilidou only won 10 points in the first set and was shut out in the second despite having triple break point in the fourth game.

Top-ranked Azarenka had her friend and musician RedFoo in the stands watching and signing autographs, and said she went onto the court listening to a "great mix of disco music and a little bit of new music. I really start to like it a lot - there's no words really."

Also advancing were No. 14 Maria Kirilenko, who beat China's Peng Shuai 7-5, 6-2, No. 16 Roberta Vinci and Elena Vesnina, who beat No. 21-seeded Varvara Lepchenko of the United States 6-4, 6-2.

On the men's side, 2008 Australian final Jo-Wilfried Tsonga beat Japan's Go Soeda 6-3, 7-6 (1), 6-3, No. 17 Philipp Kohlschreiber of Germany edged Israeli qualifier Amir Weintraub 6-2, 7-6 (4,) 6-4 and Lithuanian qualifier Ricardas Berankis ousted No. 25 Florian Mayer 6-2, 6-3, 6-1.

The lopsided wins for Azarenka and Serena Williams came a day after No. 2-ranked Maria Sharapova recorded her second 6-0, 6-0 win of the tournament.

Sharapova overwhelmed Japan's Misaki Doi in 47 minutes, even less time than she needed to beat fellow Russian Olga Puchkova two days earlier in her first competitive match of 2013.

The first woman to post back-to-back 6-0, 6-0 wins at a Grand Slam since 1985 next plays seven-time major winner Venus Williams in the third round.

The biggest upset Wednesday was 2011 U.S. Open champion Samantha Stosur's 6-4, 1-6, 7-5 loss to China's Zheng Jie.

Stosur led 5-2 in the third and wasted two chances to serve out the match, finally giving it away with a double fault on match point.

"It was a bit of a choke," Stosur said. "Obviously it's a hard one to take when you get yourself into a winning position and you lose five games straight."

No. 4 Agnieszka Radwanska, 2011 French Open champion Li Na, No. 5 Angelique Kerber and 17-year-old American wild card Madison Keys all advanced in straight sets.

Novak Djokovic also advanced to the third round, extending his winning streak at Melbourne Park to 16 with a 6-1, 6-2, 6-3 win over 20-year-old American Ryan Harrison.

He's on track for a record third consecutive Australian Open title and doesn't have any other major winners on his half of the draw after Rafael Nadal withdrew and Federer, Andy Murray and Juan Martin del Potro landed on the opposite side.

Fourth-ranked David Ferrer beat American Tim Smyczek 6-0, 7-5, 4-6, 6-3. No. 5 Tomas Berdych defeated Guillaume Rufin of France 6-2, 6-2, 6-4, and No. 8 Janko Tipsarevic took almost four hours to oust Lukas Lacko 6-3, 6-4, 3-6, 4-6, 7-5.

No. 20 Sam Querrey moved on when fellow American Brian Baker retired in the second set with an injured right knee and was pushed off Court 6 in a wheelchair.

"He's the last person that deserves anything like that with his five or six surgeries already," Querrey said.