The Belarusian dropped 17 games over five matches during the tournament to claim her first title since the Cincinnati Masters in August 2013.
The 26-year-old, who won her maiden Brisbane title in 2009, took control of the match against world number 10 Kerber after an early trade of breaks and peppered the court with her powerful groundstrokes.
"I'm not sure I feel relief," Azarenka told reporters. "I wanted to win the title, but I didn't feel, if this doesn't happen the world is going to end.
"I just feel really excited and happy that I'm doing the right things. I'm excited to keep working hard.
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"It just gives extra motivation to keep working hard and achieve better things."
Kerber, the highest seed left after the withdrawals of Maria Sharapova, Simona Halep and Garbine Muguruza, had three break points in the opening game of the second set but once Azarenka fended them off, she did not look back.
"I don't know, but for me it's always tough to play against her," Kerber said after her sixth loss against Azarenka.
"I hope one day will come where I can beat her.
"Vika was the better player today, that's all that I can say."
Azarenka won back-to-back Australian Open titles in 2012 and 2013 and has reached the U.S. Open final twice, losing both to world number one Serena Williams.
(Reporting by Sudipto Ganguly in Mumbai; Editing by Ed Osmond)
