Serena: My game is clicking
January 23, 2016 10:15 MYT
And Williams, who is yet to drop a set at Melbourne Park this year, is happy with her progress following limited preparation heading into the tournament due to a knee injury.
"I definitely think I played better today," Williams said.
"Everything I've been trying to work on was kind of clicking today. I thought I played pretty well in the other matches.
"My first match I thought I gave a great effort. My second match I thought, under the circumstances, I thought I played well.
"Hopefully with each match I can just do better."
The 21-time grand slam champion will face another Russian in the next round, with Margarita Gasparyan standing in the way of Williams and a sixth successive major quarter-final.
Of Gasparyan, Williams added: "She has a great forehand up the line. She has a good serve. She mixes up the ball well. I thought she played really well at Wimbledon. She was fearless.
"She's obviously made leaps and bounds, gained a lot of confidence. She's here to play well and win. So am I, so we'll see what happens."