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

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 Thursday over No. 112-ranked Garbine Muguruza with an ace at 128.7 mph — the fastest she can remember serving.

“I’m on the up and up, I feel. It can only get better from here,” she said, adding that she wasn’t bothered by the ankle during the match.

“Obviously when you go out to play you’re heavy on adrenaline and you’re really pumped up,” she said. “Usually I feel injuries after the match but so far, so good. I felt pretty, much better than I ever dreamed of expecting to feel.”

Williams said she was bleeding from the lip at one stage, “But it’s OK. It’s a war wound.”

“I think it happens to everyone, but I have never busted it wide open like that,” she said. “So, yeah, I was like, ‘Oh, no. I can’t have a tooth fall out.’ That would be horrible.”

Despite the injury concerns ever since needing medical timeout to treat her ankle during her first-round win on Tuesday, Williams planned to play 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 Williams’ victory, and said she’s starting to find some rhythm after beating Eleni Daniilidou 6-1, 6-0 in 55 minutes.

With temperatures expected to top 102 degrees, Azarenka didn’t want to be out in the heat.

“I felt like I’m back into the competitive mode,” she said. “I was really focused — that was for sure the best part of the game for me.”

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.”

The 23-year-old Belarusian won her first Grand Slam title in Melbourne last year, during a 26-match winning streak to start the season.

“It’s pretty difficult to duplicate something like that,” she said. “All I can do is try.”

She didn’t win another major in 2012, dropping the U.S. Open final against Serena Williams, but held the No. 1 ranking for most of the season.

The temperature hit 93 degrees during the first match of the day, and went above 104 later in the afternoon. Players wore ice vests and were shielded by umbrellas during the breaks in play.

The heat didn’t seem to bother 42-year-old Kimiko Date-Krumm, who advanced 6-2, 7-5 over Shahar Peer of Israel. She’s the oldest woman to win a singles match at the Australian Open.

Other women advancing included No. 14 Maria Kirilenko, No. 16 Roberta Vinci, No. 20 Yanina Wickmayer and Elena Vesnina, who beat No. 21-seeded Varvara Lepchenko of the United States 6-4, 6-2. Former U.S. Open champion Svetlana Kuznetsova beat 26th-seeded Hsieh Su-wei of Taiwan 6-2, 6-1.

U.S. Open champion Andy Murray had a 6-2, 6-2, 6-4 victory over Joao Sousa of Portugal. Murray, who ended a 76-year drought by British men in Grand Slam tournaments with his win at Flushing Meadows last year, didn’t allow Sousa a single break point chance in steamy conditions.

Standing in the way of a potential second Grand Slam title for Murray is a likely semifinal against No. 2 Roger Federer, who was playing his second-round match Thursday night.

Others advancing Thursday include: 2008 Australian finalist Jo-Wilfried Tsonga, who pretended to do push-ups to disguise a fall during his 6-3, 7-6 (1), 6-3 win over Japan’s Go Soeda; No. 13 Milos Raonic of Canada; No. 17 Philipp Kohlschreiber of Germany; No. 21 Andreas Seppi of Italy; and Lithuanian qualifier Ricardas Berankis ousted No. 25 Florian Mayer 6-2, 6-3, 6-1.

Novak Djokovic advanced on Wednesday night, 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 and remaining on track for a third consecutive Australian Open title.

No. 4 David Ferrer, No. 5 Tomas Berdych and No. 8 Janko Tipsarevic all went through on day three, along with No. 20 Sam Querrey, the highest-ranked American left in the men’s tournament.

Women’s No. 2 Maria 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.

“It’s not really the statistic I want to be known for,” Sharapova said. “I want to be known for winning Grand Slams.”

Sharapova leads the head-to-head series 4-3 against Venus Williams, but Williams has won both of their Grand Slam meetings.

Venus is still on the comeback trail after missing seven months after the 2011 U.S. Open to deal with Sjogren’s Syndrome.

Now seeded 25th, she dropped only one game in her first-round win and then went down a break early to Alize Cornet of France before winning 6-3, 6-3.

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.

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.