Top seed Kerber hits form in Australian Open romp

World number one Angelique Kerber say she is fired up for a last-16 clash with America's Coco Vandeweghe after blowing away Kristyna Pliskova at the Australian Open on Friday. The German defending champion, who was taken to three sets in her opening two rounds, smashed hapless Czech Pliskova 6-0, 6-4 on Rod Laver Arena as she finally got into her stride. She now faces the racquet-smashing Vandeweghe, who ended the campaign of Canadian comeback queen Eugenie Bouchard 6-4, 3-6, 7-5. "It was not so easy today, she is a tough opponent who serves well and hits the ball strongly. I tried to stay focused until the last point," said Kerber. She watched some of the Vandeweghe-Bouchard match, which preceded hers, and said she would be ready for the American on Sunday. "I think it will be a little bit similar to today, but of course, I mean, Coco is a tough opponent. She played good today," she said. "I know that she's serving good, as well. I have to move good, be ready, bring a lot of balls back, but also be aggressive as well, like I can play." Bidding to become the first woman to successfully defend an Australian title since Victoria Azarenka in 2013, Kerber had a tough time in her opening two rounds. It followed an indifferent build-up to Melbourne with early exits in Brisbane and Sydney this month. But she is starting to find her groove with the quarter-finals now in sight. "I'm ready for every single match every single day. This is what counts, because I know that this is the only way to play good tennis, especially (over) two weeks," she said. The 35th-ranked Vandeweghe threw a temper tantrum in her second-round clash against Pauline Parmentier, slamming her racquet into the ground three times when she gave away a break point. But the fiercely competitive American largely kept her emotions in check against Bouchard, only throwing down her racquet once, but not smashing it. - Blown wide open - Despite having to slog through three sets against the Canadian -- battling back after her high-flying career plunged into a tailspin -- the confident American said she always expected to win. "It was kind of expected, in my mind, to get the win and to get the victory and to move a step closer to achieving what I want to achieve for this year and also this tournament," she said. She added that she never considered that she might lose a match, and that she would apply the same mindset to the clash with Kerber. "If you're already thinking you're going to lose to anybody, you have already lost before you have taken a step out there and played the first point or started the warm-up," she said. The women's draw at Melbourne Park has been blown wide open with the early upsets of third seed Agnieszka Radwanska and fourth ranked Simona Halep. But worryingly for Kerber, Serena Williams -- the woman she beat in last year's final, and then replaced as world number one -- is still in the hunt and looking ominous. Williams, chasing a 23rd Grand Slam title, raised a lone index finger after her round two win on Thursday in a gesture many interpreted as the American indicating she still considers herself number one.