The Belarusian was forced to save two match points deep in the second set before seeing off the bullish Kerber and get an opening victory under her belt in Turkey.
In a brilliant advert for the women's game, Kerber point blank also refused to lie down and concede defeat, twice fighting back from a break down in the final set before eventually succumbing in three hours and six minutes.
"It was definitely a great fight," Azarenka said. "I'm more proud of the way I handled and stayed in that match."
Azarenka, playing her first match of the tournament, appeared on course to claim the first set as she broke back in the sixth game before earning herself four set points in the opening tie-break.
But, as was to become a feature of the match, Kerber refused to give it up; the German saving all four of those set points, plus a handful more, as she snatched an epic first set 13-11 when Azarenka overdid a baseline drive.
The second set followed in much the same manner, albeit with Azarenka breaking first.
The Belarusian got ahead in the opening game, as Kerber suffered a temporary and understandable comedown after the elation of taking the first set.
The defining characteristic of the match, however, was fighting spirit and, after a series of solid service holds for both players, Kerber broke back in the eighth game when Azarenka suffered a lapse in concentration.
Saving four break points in the following game only increased Kerber's confidence as she marched towards an unlikely victory, setting up two match points in the 10th game.
Azarenka looked ready to implode as successive errors saw the emotional Belarusian fling her racquet to the ground in disgust to a cacophony of boos and wolf-whistles from the crowd.
Never one to let a negative crowd get to her, Azarenka harnessed that emotion brilliantly and aggressively saved the two match points before going on to take the second set 7-2 in a much more straightforward tie-break.
The match appeared to be all but won for Azarenka as Kerber looked tired struggled in the opening couple of games of the final set.
A forehand winner down the line sealed the early break for Azarenka as she looked to capitalise on Kerber's disheartened state of mind.
But once again Kerber bounced back, breaking straight back in the very next game with back-to-back forehand winners.
After a couple of solid service holds, allowing both the players and the crowd to catch their breath, Azarenka again took the break lead; Kerber slapping down just her fourth double fault in the process.
But just like on previous occasions, Kerber immediately levelled things up, breaking back in the next game when Azarenka hit a backhand long under extreme pressure.
This time, however, it was a step too far for the German, as she still had to serve to stay in the match.
Azarenka was quick to set up two match points of her own and eventually wrapped up the match at the first attempt when Kerber sent a cross court backhand narrowly wide.
In a further blow to the German, the defeat leaves her unlikely to make the semi-finals of the round-robin tournament, while Azarenka - who plays Serena Williams on Thursday - needs just one more win to secure the world number one ranking for the end of the year.