The leading five seeds at the WTA San Diego Open sailed into the quarter-finals on Thursday, with only China's number four Peng Shuai taken the three-set distance.
Top-seeded Vera Zvonareva paced the attack of the elites as she hammered fellow Russian Vera Dushevina 6-3, 6-0.
German second seed Andrea Petkovic needed a mere 43 minutes to advance as French opponent Virginie Razzano retired with a shoulder injury while trailing 6-2, 3-0.
Third-seeded Agnieszka Radwanska had to cope with shoulder pain caused by a nerve problem, but persevered to crush American teenager Christina McHale 6-1, 6-0.
"I played better than in my first match, everything was working," said Radwanska, but she admitted: "I'm worried about the shoulder. I'll have to get it looked at.
"It seems every time I come on the the hardcourt in summer it gives me trouble. It's tough to treat."
Radwanska said that despite her runaway victory "my serving was not at 100 percent. I just hope everything will be OK."
Peng was the exception to the quick-win rule, taking two hours, 39 minutes to defeat Italian 15th seed Sara Errani 4-6, 6-2, 7-6 (9/7).
Fifth-seeded Serb Ana Ivanovic was buoyed by by her 6-1, 6-2 defeat of Italian Alberta Brianti and next faces Peng.
"There were a lot of close, games, overall I played very well," said the former number one and 2008 Roland Garros champion who is now ranked 18th.
"I was patient. If you give her chances she can do damage. I stayed clam and executed my shots like I've been doing in practice," said Ivanovic, who recently hired Briton Nigel Sears as a coach.
Zvonareva posted her sixth victory in nine matches against Dushevina and reached her ninth quarter-final of the season.
"It was an improvement over my first match," said Zvonareva, a finalist at Wimbledon and the US Open in 2010.
"I started slow and had some ups and downs," added Zvonareva, who won the last nine games of the match. "I was able to go for my shots and played well on the key points. I never gave her a chance to turn it around or get back into the game."
Petkovic, who arrived at the resort site of La Costa six days early and has been happily partaking of the luxury amenities with her sister, will next play American surprise packet Sloane Stephens after the 18-year-old advanced when Austria's Tamira Paszek retired with a right abdominal strain while trailing 5-3.
Petkovic is rationing her American events leading to the August 29 start of the US Open in order to avoid any chance of burnout.
"I had no expectations coming here," said the world number 11, who is playing her first tournament since Wimbledon.
"I prefer staying at home until the last minute and practicing. It's a long summer trip over here for Europeans."