Serena Williams of the US hits a forehand return to Spain's Garbine Muguruza during their second round match at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 17, 2013. Britain's Andy Murray signs autographs following his win over Portugal's Joao Sousa in their second round match at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 17, 2013. Victoria Azarenka of Belarus blows kisses to the crowd following her win over Greece's Eleni Daniilidou in their second round match at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 17, 2013. Rajeev Ram of the US wipes the sweat from his face during his second loss to Croatia's Marin Cilic at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 17, 2013. Australia's Bernard Tomic celebrates after defeating Germany's Daniel Brands in their second round match at the Australian Open tennis championship in Melbourne, Australia, Thursday, Jan. 17, 2013. MELBOURNE, Australia (AP) - With temperatures well over the 100-degree mark, Serena Williams and Victoria Azarenka were in no mood to stick around on the searing courts at the Australian Open. A dancing Azarenka and an ankle-weary Williams played back-to-back matches Thursday on Rod Laver Arena, both easy straight-set victories. U.S. Open champion Murray also won routinely, beating Joao Sousa of Portugal 6-2, 6-2, 6-4 on Hisense Arena, the second show court at Melbourne Park. "You need to be the one that's trying to dictate the points in these conditions," said Murray, who practices in Florida. Miami is the perfect preparation. It's hot and humid there, although it certainly doesn't get up to 37 degrees (Celsius; 99 Fahrenheit). It was a good match to get done in straight sets.  Despite the high temperatures - it later peaked at 106 F - tournament officials left the retractable roofs on both main arenas open because a combination of factors including humidity and court temperature didn't warrant making the venues a temporary indoor haven from the heat. Ice vests and towels helped players keep their cool, and a women's tour rule allowing a 10-minute break between sets was invoked late in the day, tournament director Craig Tiley said. "It's always the referee's discretion, but the lack of humidity helped us today," Tiley said. Australia sweltered through a week of record high average temperatures earlier this month, but the first three days of the Open were relatively mild. Second-seeded Roger Federer, who could face Murray in the semifinals, got the luck of the draw and was scheduled to play a night match on Rod Laver later Thursday. Williams went into Thursday's match with an injured right ankle. She didn't seem troubled by the ankle, but did finish with a swollen lip after hitting herself with her racket. "It's OK," she said. I think it happens to everyone, but I have never busted it wide open like that. I was like, 'Oh, no. Williams lifted her tempo on the biggest points, including when she finally won an 18-minute game to open the second set en route to a 6-2, 6-0 win over Garbine Muguruza. 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 of her ankle. She later combined with sister Venus to win in the first round of doubles, showing no signs of trouble with the ankle. The top-ranked Azarenka pranced into Rod Laver Arena for the first match of the day, and said she's starting to find some rhythm after beating Eleni Daniilidou 6-1, 6-0 in 55 minutes. "I felt like I'm back into the competitive mode," Azarenka said. 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." 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 former No. 1-ranked Caroline Wozniacki, No. 14 Maria Kirilenko, No. 20 Yanina Wickmayer and Elena Vesnina, who beat No. Former U.S. Open champion Svetlana Kuznetsova beat 26th-seeded Hsieh Su-wei of Taiwan 6-2, 6-1. 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. When the sun came out, it was extremely hot. When it wasn't, it was fine. There was no humidity," he said, playing down the impact of the hot conditions. When you get the combination of the heat and the humidity is when it's normally at its worst. I've played in worse conditions. Among the other men advancing was 2008 Australian finalist Jo-Wilfried Tsonga, who pretended to do pushups to disguise a fall during his 6-3, 7-6 (1), 6-3 win over Japan's Go Soeda. Australia's Bernard Tomic went through to the third round along with No. 17 Philipp Kohlschreiber of Germany, No. 21 Andreas Seppi of Italy and Lithuanian qualifier Ricardas Berankis, who beat No. Tomic beat Novak Djokovic at the Hopman Cup and won last week's Sydney International, his first ATP tournament victory. He has won 10 matches in a row and has held 76 consecutive service games through that stretch. He could face Federer in the third round, provided the Swiss star wins Thursday night. "If the opportunity comes, it's going to be an interesting match," Tomic said of the potential Sunday encounter. Djokovic plays his third-round match on Friday, while the featured women's match will be second-seeded Maria Sharapova's eighth career meeting with Venus Williams. Sharapova holds a 4-3 edge, although Venus has won both times they've met in Grand Slams - at Wimbledon.