Azarenka, Wozniacki feel the heat as Melbourne scorches

Victoria Azarenka made a stuttering start to her bid for a third straight Australian Open title on Tuesday when she was kept out in the Melbourne heat for 106 minutes by Johanna Larsson before sealing her place in the second round.

Organisers tried to mitigate temperatures in excess of 40 degrees Celsius by providing towels packed with ice, hundreds of bottles of water and an extra 10-minute break between the second and third sets for the women's matches.

Azarenka had no need of the extra 10-minute break after wrapping up her match 7-6(2), 6-2 despite having her service broken three times in the opening stanza of an absorbing contest and twice facing the Swede serving for the first set.

"First matches can be tricky and the weather is not really helping," the Belarusian said on court after her win set up a meeting with Czech Barbora Zahlavova Strycova.

"But was really glad to win that first set, it was really important and then I played better in the second."

Romanian 11th seed Simona Halep, who last year won six titles and was named most improved player on the women's tour, took 54 minutes to beat Katarzyna Piter 6-0, 6-1 in the first match on Margaret Court Arena.

Former world No 1 Caroline Wozniacki lost her serve early in the second set but swept into the second round with a 6-0, 6-2 victory over Spain's Lourdes Dominguez Lino.

"Was this before the heat? Jeez it was hot out there, felt like I was playing in a sauna or something," the Danish 10th seed said after her 67-minute contest.

"I was just trying to take the ice-towel as much as I could."

Three of the ‘Big Four’ of men's tennis also get their campaigns underway on Tuesday with Roger Federer and Andy Murray braving the daytime heat, while World No 1 Rafael Nadal faces Bernard Tomic in the relative cool of the evening.

Men's number 21 seed Philipp Kohlschreiber withdrew from the tournament with a recurrence of a left hamstring problem before his match against Aljaz Bedene, who was instead defeated 7-6(3), 6-3, 6-0 by French lucky loser Stephane Robert.

It was not just the players who were struggling as a ballboy on court eight required medical treatment after fainting during Milos Raonic's 7-6(2), 6-1, 4-6, 6-2 victory over Daniel Gimeno-Traver.

The tournament is already over for America's No 1 John Isner, who had been struggling with an ankle problem and retired while trailing Martin Klizan 6-2, 7-6(6) in his first round contest.

While the men's 13th seed gamely played on for 82 minutes, Slovenia's Polona Hercog retired with a shoulder injury after just six points of her first round contest against France's Alize Cornet on court six.