MELBOURNE, Australia -- Victoria Azarenka began her bid for a third consecutive Australian Open title with a 7-6 (2), 6-2 win over Johanna Larsson on Tuesday as the predicted heat wave arrived at Melbourne Park.
Third-seeded Maria Sharapova also advanced when she beat American Bethanie Mattek-Sands 6-3, 6-4 in the last match of the night. Mattek-Sands double-faulted on break point in the ninth game of the second set, and Sharapova served out.
Second-ranked Azarenka had a tougher time at Rod Laver Arena against Larsson, who twice had chances to serve for the first set but lost it in a tiebreaker.
"Yeah, it was a tough set first. The match was going to be tricky ... the weather was not helping," Azarenka said. "I had to play a little bit and find my rhythm."
Both players had trouble holding serve, with a combined six breaks in 66 minutes leading into the tiebreaker. No. 91-ranked Larsson was taking big cuts with her ground strokes and forcing Azarenka to defend in the first set. The two-time defending champion started getting on top in the second and didn't drop serve once. Both players draped bags of ice over their necks and shoulders and sat under cover during the changeovers. They retreated into the shade at the back of the courts between points.
Azarenka said it felt "pretty hot, like you're dancing in a frying pan or something like that."
After her win, Azarenka went back out to practice and said she planned an ice bath later as a recovery.
Temperatures hit 108 degrees on the second day of the tournament, with the forecast predicting more heat until Friday. A hot, gusty breeze swirled across the venue all day, making conditions more challenging instead of cooler.
Some players struggled. Canadian qualifier Frank Dancevic said he blacked out during a 7-6 (12), 6-4, 6-3 loss to No. 27 Benoit Paire of France. Dancevic received treatment in the second set but continued. On the women's side, Peng Shuai got sick on court but also continued her match.
A ball kid was treated for heat stress during a morning match. Meanwhile, spectators on outside courts covered their heads and shoulders with damp towels to cool off, and queued up to stand in front of large electric fans blasting water at their faces. The crowd for the day session was 35,571, down almost 12,000 from Day 1.
With the hot conditions forecast to last at least until Friday, the higher-ranked players were desperate to progress quickly.
Wozniacki said the court was so hot in her 6-0, 6-2 win over Lourdes Dominguez Lino, which started at 11 a.m., that it seemed to melt her plastic water bottle.
In her first Grand Slam match since her New Year's Eve engagement to golfer Rory McIlroy, she did everything she could to keep cool.
"Every time in the changeovers, ice bags, ice towels, everything. And then in the second set, I could feel they were starting to heat up even more," Wozniacki said. "I put the bottle down on the court, and it started melting a little bit underneath, the plastic, so you knew it was warm."
After the win, she sat on her bench, pulled her engagement ring from her tennis bag and slipped it on her finger. An on-court interviewer asked her to hold it up for the crowd and recount the proposal, which she said was very traditional.
"He asked my parents," she said. "He went down on one knee."
She added that he chose her favorite number -- eight -- in carats. Wozniacki, now ranked 10th, said she didn't expect marriage would change her professional priorities and said that if anything, it would bring a new "calmness" to their lives.
"We know what we want, and it just gives us even more time to focus on our careers," she said.
"For me right now, I try to focus on the Grand Slams," added Wozniacki, who was a 2011 semifinalist in Melbourne and a two-time semifinalist at the US Open. "That's what I'm missing on my résumé. So that's obviously what I would like to achieve."
Wozniacki will face American Christina McHale in the second round.
Garbine Muguruza of Spain, a recent champion in Hobart, beat No. 24 Kaia Kanepi.
The Associated Press contributed to this report.