Top seed Justine Henin and defending champion Serena Williams reached the last 16 of the Australian Open with straight-sets wins on Friday.
Henin has yet to reach anything like top form in Melbourne
Henin had to work hard before defeating Italy's Francesca Schiavone 7-5 6-4, while Williams showed good form to beat Victoria Azarenka 6-3 6-4.
Williams next meets Nicole Vaidisova, who beat Ai Sugiyama 6-3 6-4.
Fifth seed Maria Sharapova looked sharp as she demolished fellow Russian Elena Vesnina 6-3 6-0.
And third seed Jelena Jankovic endured some tense moments on her way to a 6-2 4-6 6-1 win over Virginia Razzano.
"I found some energy somehow and managed to pull it through," said Jankovic.
I'm feeling pretty good about where I am
Henin extended her winning streak to 31 matches but continued to look rusty, as she had in her earlier matches in Melbourne.
"I hate to look too far," said Henin, who will face Hsieh Su-wei in the fourth round before a possible meeting with Sharapova.
"I just want to get ready, improve my game and be in my best shape. I know the draw, but I like to stay concentrated on myself."
The Belgian got the better of the first set against Schiavone with three of five service breaks and looked on course for a relatively straightforward win at 4-1 in the second.
Schiavone battled back and had two break points to level at 5-5 but could not convert, and Henin closed out with three straight points.
"It was really exciting," said Henin. "I'm glad to win in two. She's always given me trouble in the past, so it was a tough third round for me."
Williams fired 15 aces as she saw off former junior number one Azarenka, and said: "I'm feeling pretty good about where I am, I'm just enjoying every moment being here."
Sharapova was equally pleased with her swift win over Vesnina, and brushed off concerns about being in the tough half of the draw with Henin and Williams.
"After the three-all game I thought I did a good job of stepping
up and playing good," she said.
"I think she came out with not much to lose and hitting the balls big, but when it got close that's where I felt I had the advantage.
"Whether that is experience or her getting tight I don't know but I am pleased.
"Of course, it's only going to get tougher, but you know me, I like those challenges and I look forward to them."
Russia's Elena Dementieva, seeded 11th, demolished 17th seed Shahar Peer of Israel 6-2 6-0 to earn a meeting with Sharapova in the fourth round.