Top players waste no time in Australian Open heat

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. "It's a war wound. I think it happens to everyone, but I have never busted it wide open like that. I was like, 'Oh, no. I can't have a tooth fall out.' That would be horrible."

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.