The Belarussian took 77 minutes to dismantle her unseeded Czech opponent 6-2 6-2 in bright sunshine on Rod Laver Arena and set up a clash against eight seed Agnieszka Radwanska, who had an even easier time of it against Julia Goerges, beating the German 22nd seed 6-1 6-1.
The match only really sprang to life when Benesova fought off four match points and Azarenka felt the fire in her belly.
Brow furrowed below her lime-green headband, Azarenka cursed and cajoled herself to close out the match, shrieking in victory with a crunching forehand winner.
The Belarussian is not a universal crowd favourite, but few provide better entertainment.
Azarenka won the title over a strong field at the Sydney warm-up event last week and has stormed through the first week at Melbourne Park with four emphatic victories.
A tough offseason of physical and mental training has begun to pay off and while many of her rivals in the women's game are struggling with injuries, the 5ft-11in (180cm) righthander is in peak condition.
Top seed Caroline Wozniacki, Kim Clijsters and Serena Williams all came into the tournament with injuries, while Maria Sharapova was forced to pull out of the Brisbane warm-up event due to an ankle issue.
Azarenka said the influence of power on the women's game was taking its toll.
"The game has become so physical, the speed, the power that we play with is so much higher than before," she added. "The slides, the stops, it's way tougher on the body and I think that's the answer."
Azarenka, who says she would like to give acting a try at some point, has no problem with the criticism she receives for her infamous 'grunting' during games.
Even the mocking imitations from a partisan crowd during her win over local hope Casey Dellacqua in the second round on Wednesday got under her skin.
"It has become part of my breathing, part of my moving, part of my game," she said with a shrug and a smile. "It's part of who I am."
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