Melbourne - Seventh seed Angelique Kerber thumped compatriot Annika Beck to win an all-German clash and reach the Australian Open quarter-finals for the first time on Monday.
The 28-year-old, who had a stellar 2015 but underachieved at the majors, eased past Beck 6-4, 6-0 and will play either two-time champion Victoria Azarenka or Czech Barbora Strycova in the last eight.
"The first set was certainly close, up and down. I just tried to be aggressive and take my chances," said Kerber.
"I'm very happy to be in the quarters for the first time. I'm looking forward to my next match and let's see how far I can get."
Kerber was a form player coming into Melbourne Park, winning four titles last season -- second only to Serena Williams, who claimed five - but she failed to translate that to the Grand Slams.
She was sent packing in the third round or worse at all four majors, with her quarter-final appearance here the best she has managed in nine attempts in Melbourne.
Kerber opened this season with a run to the final of the Brisbane International, where Azarenka beat her, but struggled in her opening match here, surviving a match-point scare.
But the left-hander has been steadily getting better, with Beck, ranked 55, always the underdog, having only once beaten a top 10 player - Simona Halep in 2014.
Beck, the French Open junior champion in 2012, seemed overawed by the occasion and quickly lost her opening serve as Kerber dictated the baseline battle with some heavy hitting.
The more experienced German comfortably held her own serve before Beck settled down and started getting into the contest.
She began matching Kerber from the baseline and created five break points in the fourth game, finally converting with a delicate backhand chip.
But it was a short-lived advantage with Kerber immediately breaking back.
Neither player could hold serve as they traded breaks in an energy-sapping clash before Kerber came through a brutal rally for a 5-4 lead when Beck slammed a backhand into the net.
Kerber finally held her serve to take the first set in 60 minutes.
The talented but unproven 21-year-old Beck was in the second week of a major for the first time in 14 career appearances, and experience was clearly a factor in the second set.
Kerber stepped it up a notch, forcing a growing number of errors from Beck, who slapped a forehand long to be broken in her opening service game.
It only got worse as Kerber pushed her opponent around the court, quickly racing to a 5-0 lead as Beck lost the plot, with a net volley allowing Kerber to become the first German to reach the last eight in Melbourne since Andrea Petkovic in 2011.