Dominant Azarenka into Brisbane quarter-finals
Victoria Azarenka of Belarus hits a backhand to Casey Dellacqua of Australia in their match at the Brisbane International in Brisbane, Australia on January 1, 2014
Second-seeded Azarenka had far too much firepower for Dellacqua, winning 6-3, 6-1 to book a quarter-final berth against unseeded Swiss Stefanie Voegele.
A day after top seed Serena Williams was pushed hard by Andrea Petkovic, Azarenka was never in any trouble against Dellacqua.
The Belarusian smashed 18 winners and made only 11 unforced errors, making 75 percent of her first serves in a solid start to the year.
The world number two, who won her maiden WTA title in Brisbane in 2009, beat Williams in an exhibition in Thailand late last year and showed enough to suggest she would be a danger to the American both in Brisbane and at the Australian Open, where she is defending champion.
"First match, I think, you can't look for perfection in the first match because you will always be a little bit rusty and still feel a little bit of hesitation," Azarenka said.
"If you look overall, I think it was a good match.
"I took my chances on the important moments. I did a few mistakes, but that's very normal.
"But overall I think the game was pretty good. From here you can only start to build up your form."
Earlier the spate of withdrawals at the season-opening tournament continued with two more women pulling out.
German seventh seed Sabine Lisicki withdrew with a gastrointestinal illness before her match against Voegele, while 2013 runner-up Anastasia Pavlyuchenkova retired with a leg injury against fifth seed Angelique Kerber.
Kerber was leading 6-2, 4-3 at the time and now goes on to play fourth seed Jelena Jankovic in the quarter-finals.
Eighth seed Caroline Wozniacki pulled out with a shoulder injury before the tournament started, while Australian qualifier Ashleigh Barty withdrew late Tuesday with a groin problem, handing Maria Sharapova passage through to the quarter-finals.
Kerber said she could not explain why there were so many injuries, although she did point out that there was a big difference between practice and match play.
"It's so much different when you go out there and you play against the opponents (rather than practise against them)," she said.
"I mean, I'm feeling good, so I don't know what (problems) the others have."