Serena Williams believes she produced one of her finest serving displays in her thrashing of Maria Kirilenko at the Australian Open on Monday night.
Making 87 percent of first serves and hitting six aces, Williams only conceded eight points when serving in her 6-2 6-0 win over the Russian 14th seed in their fourth-round match.
Williams needed just 57 minutes to advance to the quarter-finals, and said she hopes to continue serving as well as she did against Kirilenko.
"I definitely have never hit that high of a percentage because I take a lot of chances with my serve," she said.
"It was good, but I really want to be able to keep it up.
"I was surprised (by my performance). I felt like Maria played really well. I was just trying to play well, just to keep up."
Williams has dropped just eight games on her way to a quarter-final meeting with countrywoman Sloane Stephens.
The 31-year-old said she had been happy with her fighting qualities through her first four matches.
"Consistency, fighting. I'm really out there just doing the best I can, just fighting for everything," Williams said.
"I think with that attitude I'm just trying to stay in the tournament just to stay alive."
Williams was too good for Stephens when the pair met at the Brisbane International at the start of the year.
She said she was pleased to see the teenager doing well at a grand slam.
"I'm here to compete and do the best I can, as well as she. And she's been doing really amazing. I'm really happy," Williams said.
"I have a tough match, so we'll see."
Stephens, speaking after her 6-1 3-6 7-5 win over Serbian Bojana Jovanovski and before Williams had thrashed Kirilenko, said it was just 'another match'.
"It will be fun. Same thing. Just go out there, another match, another day," she said.
"Obviously, it's quarters of a grand slam, so you've just got to do your best."