China's Li Xuerui blasted away compatriot Han Li as she strode into the quarter-finals of the women's singles at the badminton world championships on Thursday.
World number one Li started the contest against her 12th-seeded opponent in irresistible form before closing out an emphatic 21-9, 21-17 victory in just 27 minutes in Copenhagen.
"We're team-mates so we're quite familiar with each other," said Li afterwards.
"Even in Chinese team competitions she does quite well, she's not an easy opponent," added the top seed before calling out her upcoming opponent in the last eight, India's Saina Nehwal.
On Wednesday Saina called for the Badminton World Federation (BWF) to reduce the number of entrants per country at international tournaments to curb China's dominance in the sport.
Top-ranked Li, one of four Chinese representatives in the women's draw, responded by saying: "Let her beat me first...she still has to face (Chinese players) whether there's two or three of us.
"Even if an opponent isn't in the Chinese team of course she can still win. If she's not strong enough then that's her own problem."
Saina, bronze medallist at the London Olympics, set up a showdown with Li in the quarters after overcoming a patchy start to claw her way past Japanese 13th seed Sayaka Takahashi 14-21, 21-18, 21-12.
A day earlier the Indian had said it was "mentally draining" having to face a host of Chinese opponents in every tournament and she needed all of that resolve on Thursday to keep herself in the world championships.
"I was bit slow physically at the start. She was playing some sharp shots and I wasn't moving very well. Perhaps I didn't warm up that well.
"But I stayed mentally tough and played my best in the second and third games," Saina said following an hour-plus duel with Takahashi.
On her impending encounter with Li, the runner-up from Guangzhou a year ago, Saina admitted she would have to perform at her peak.
"It won't be easy but I will give my best. I'll need to be quick and very fast around the court and be ready for some quick shot just like against Sayaka," the seventh seed said.
South Korea's Sung Ji-hyun, the fifth seed, swept aside Lindaweni Fanetri of Indonesia 21-10, 21-16 while Taiwanese eighth seed Tai Tzu-ying ended the run of Canada's Commonwealth champion Michelle Li with a 21-16, 21-11 win.