An error-riddled performance from Carina Witthoeft aided Angelique Kerber as the defending champion advanced to the Australian Open third round in three sets on Wednesday.
A mix of solid defence and Witthoeft's errors saw world number one Kerber claim a 6-2 6-7 (3-7) 6-2 win over her German counterpart at Melbourne Park.
After looking comfortable in the opening set, Kerber was clawed back by Witthoeft, who played some of her best tennis in the second, reeling off six consecutive points in the tie-break to force a decider.
But Kerber's experience and quality was telling as the two-time grand-slam champion outlasted Witthoeft to earn a showdown with either Irina-Camelia Begu or Kristyna Pliskova in the third round.
Witthoeft was her own worst enemy from the outset, with a sun-bathed Rod Laver Arena rattling the German, who served up three double faults in the opening game to hand Kerber an early break.
Kerber was immediately broken back by Witthoeft however, only to regain the break of serve to love in the third.
Witthoeft, again, gifted Kerber a point and the game as the 2016 Olympic silver medallist consolidated for a 3-1 lead.
It was more of the same from Witthoeft in the seventh game, firing a forehand long to give Kerber the double break and she served it out to love to claim the opening set.
Kerber continued where she left off in the second set, using a powerful passing cross-court forehand to set up a break point, which she converted.
But Witthoeft found her range as the match wore on, settling into her groove to earn three break points and she executed at the third time of asking to level the set at 2-2.
Witthoeft maintained her resurgence, making Kerber work for her points but the latter's defence was impenetrable at times as she claimed an important hold of serve in the eighth game.
The pair could not be separated heading into a tie-break and Kerber stumbled dramatically, surrendering a 3-1 lead as two double faults and two unforced errors gifted Witthoeft the second set.
Witthoeft threatened to cause an upset after breaking in the first game of the deciding set but that only sparked Kerber into action, with the US Open champion showing no mercy on her 29th birthday to improve to 3-0 in their head-to-head record.
Kerber  bt Witthoeft 6-2 6-7 (3-7) 6-2
Kerber – 26/34
Witthoeft – 38/69
Kerber – 3
Witthoeft – 3
BREAK POINTS WON
Kerber – 7/9
Witthoeft – 3/10
FIRST SERVE PERCENTAGE
Kerber – 59
Witthoeft – 69
PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Kerber – 65/51
Witthoeft – 64/28
Kerber – 107
Witthoeft – 92