Stunned Kerber at a Loss over Early Exit

World number one Angelique Kerber was left licking her wounds Sunday and trying to work out what went wrong after crashing out early in her first Grand Slam title defense.

The German, who beat Serena Williams to win the Australian Open last year and followed it up with the U.S. Open title, looked anything but a top seed as her game was dismantled by 35th-ranked Coco Vandeweghe.

Kerber never looked at her peak, having to battle through tough three-setters in her opening two rounds at Melbourne Park, following an indifferent build-up with early exits in Brisbane and Sydney this month.

Confident American Vandeweghe swept past her 6-2, 6-3, leaving Kerber bitterly disappointed.

"It was a tough match, and of course I'm disappointed. But I was not feeling the ball at all tonight. I was not playing good from the first point. It was not my day," she said.

"I missed a lot and I make a lot of unforced errors. So this was not my game like I play normally."

Kerber, 29, was not only defending a Grand Slam for the first time, but was also in her first major tournament as world number one, but she denied the pressure got to her.

"Of course, they were new experiences. This is good, they are new challenges," she said. 

"I can learn from all the other stuff which is new for me. I mean, let's see. It's just the beginning of the year. I can still improve my tennis, which is good.

"I will try my best to come back stronger."