Flawless Maria Sharapova set a new Australian Open record Sunday in losing just five games en route to the quarterfinals, where she was joined by fellow Russian Ekaterina Makarova.
The second seed has been in impeccable form and she thrashed unseeded Belgian Kirsten Flipkens 6-1, 6-0 to set up a meeting with 19th seed Makarova, who knocked out world number five German Angelique Kerber 7-5, 6-4.
World number four Agnieszka Radwanska of Poland plays Serbian 13th seed Ana Ivanovic, and sixth seed Li Na of China takes on German Julia Goerges in Sunday's other fourth round matches.
Sharapova, the 2008 champion, has only dropped five games in four matches so far in her bid for a second Australian title, the fewest games conceded to make the quarters in Melbourne in the Open era.
Monica Seles (1991 and 1993) and Steffi Graf (1989) previously held the record at eight games.
But Sharapova missed out on the all-Grand Slam mark held by Mary Pierce, who dropped only four games in making the last eight at the French Open in 1994.
"I'm certainly happy that I'm playing this well but it's now the quarter-finals and it only gets tougher," Sharapova said, adding that it was important to keep her concentration.
"It's really about keeping your focus, no matter what the score is, no matter if you're up."
She added: "I didn't start the match really great. I was facing a different type of opponent today and I was making a few more mistakes than I would have liked in the beginning.
"But after I held at 2-1, I really started making her play a little bit more."
The second seed had beaten Flipkens in both of their previous matches but they tested each other in the first game, which the Belgian finally won.
Sharapova, who needs to reach the final to have a chance of returning to world number one, held serve and then, helped by some loose Flipkens shots, got the break for 2-1 with a blistering crosscourt forehand winner.
Flipkens had two break point chances in the next game but failed to convert as Sharapova held.
The four-time Grand Slam winner, who defeated Venus