Top seed Kerber battles into second round
The top seed ultimately proved too much for Lesia Tsurenko, winning 6-2, 5-7, 6-2 on Rod Laver Arena.
The top seed ultimately proved too much for the Ukrainian, winning 6-2, 5-7, 6-2 on Rod Laver Arena and but the German's laboured victory was far from impressive.
Kerber, 28, stunned Serena Williams in the final last year and went on to win the US Open, dethroning the American powerhouse as the world's top ranked player.
She is not only defending a major title for the first time but also playing her maiden Grand Slam as top seed, admitting ahead of the tournament that she was carrying the burden of expectation.
She seemed to be struggling under that pressure early in the game, taking time to get into her groove. Once she did, there was no stopping her until Tsurenko came back to life late in the second set.
"The first round is always tough. I'm just trying to enjoy it and I'm so so happy to be in the second round," Kerber said.
"I'm really happy to be back in Melbourne because everything started for me here in 2016."
Bidding to be the first woman to defend her Australian title since Victoria Azarenka in 2013, the left-hander initially struggled to read the Ukrainian's serve.
Tsurenko, ranked 51 and in her seventh Australian Open, raced through her opening service game to love and Kerber had to save a break point in the next game to stay level.
Tsurenko kept the pressure on, firing down another love service game with the German seemingly at a loss.
But she finally got her eye in to break in the fifth game for a 3-2 lead and there was no looking back as she unleashed some powerful groundstrokes to take the first set in 27 minutes.
Tsurenko's confidence had taken a hit after losing six games in a row, including being broken in the first game of the second set, but she dug deep to rally and hold serve.
It looked like it was only delaying the inevitable but Kerber lost focus and failed to convert a match point in the 10th game, with the determined Tsurenko pouncing to break back and level the set at 5-5.
On a roll as Kerber flagged, she took the match to three sets when she converted a fourth set point while leading 6-5.
Kerber, who had an indifferent lead-up with early exits in Brisbane and Sydney this month, was rattled but regrouped for the deciding set, claiming the edge when the Ukrainian whipped a backhand wide in the fifth game to be broken.
The German kept her nerve and served out for the match to set up a second-round clash with fellow German Carina Witthoeft, who beat Japanese qualifier Eri Hozumi 7-5, 7-6 (8/6).