Angelique Kerber: 'This was not my normal game'

Angelique Kerber said that she was simply punished for an off-day after her Australian Open title defence ended at the hands of an inspired Coco Vandeweghe on Sunday.

Angelique Kerber - cropped

World No. 1 Angelique Kerber following her loss to Coco Vandeweghe.

Angelique Kerber said that she was simply punished for an off-day after her Australian Open title defence ended at the hands of an inspired Coco Vandeweghe on Sunday.

Top seed Kerber was emphatically >dumped out in the fourth round at Melbourne Park as World No. 35 Vandeweghe delivered a superb display of power-hitting on Rod Laver Arena.

In a post-match news conference, Kerber said: "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 and not my match, for sure."

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

Having failed to make the second week of her first grand slam as the World No. 1, Kerber is confident she can bounce back.

"I learned a lot, and I have new experience now. I mean, I'm looking forward to all the next tournaments that are coming," said the German.

"Of course, they are new experiences [defending the title and playing as world number one]. This is good, they are new challenges. I can learn from all the other stuff which is new for me. 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, coming back stronger."

Vandeweghe — a quarterfinalist at Wimbledon in 2015 — will go on to face Garbine Muguruza in the last eight.