The third seed from Belarus eventually won 6-2 6-4 in just under 90 minutes, but her inability to Barthel away prompted a furious tirade at a line judge.
Azarenka admitted after that she may have overreacted having let her emotions get the better of her.
"I'm a very emotional player. If you ever watched my matches, you know I try to control my bad emotions, but that wasn't the case really today," she said.
"The beginning of last year I think it was the last time, breaking racquets, having that almost crying face on the court as a lot of players do."
As well as clashing with a line judge, Azarenka had to deal with a section of the crowd that mimicked her loud grunts whenever she played a shout while she was booed on match point on Hisense Arena.
However the 22-year-old insists that the taunts do not concern her.
"Of course I hear it, I'm not deaf," she said. "I have no problem with that at all actually, I knew it was going to happen.
"They wanted her to win bad. It's fine with me, doesn't really bother me.
"I respect the crowd. Whatever they do, I try to just be focused on my game, and that's it."
Azarenka will now face Iveta Benesova, a 6-1 6-3 winner over Russian qualifier Nina Bratchikova, in the next round.