Serena Williams believes Wimbledon fans will throw their support behind her sister Venus when the two five-time champions square up on Monday.
The grand slam supremos will play for the 26th time in 17 years, after Serena squeaked past Britain's Heather Watson and Venus defeated Aleksandra Krunic to reach the last 16.
Serena admitted "I would be rooting for Venus" should she be just a face in the SW19 crowd, after her older sister's battles with auto-immune disease Sjogren's syndrome.
The 33-year-old also hailed 35-year-old Venus as the Williams sibling in the better form, hinting at a titanic fourth-round tussle next week.
"I expect more people to be rooting for Venus," said Serena. "I would be rooting for Venus. She's been through so much. She's had a wonderful story.
"She's been so inspiring to me; she's just an incredible individual.
"She's just so amazing. She's been so inspiring to a lot of people with the same things that she goes through, too."
Serena fought off two match points to tiptoe past luckless British number one Watson 6-2 4-6 7-5, while Venus battered Aleksandr Krunic 6-3 6-2.
The younger Williams believes even 12 months ago she would have been unable to turn the tide against Watson when the home hope applied the pressure.
"I think this is a match I would have lost last year or the year before," said Williams of her three-set tussle with Watson.
"The older I get, I think the tougher I get upstairs."
Serena boasts 14 wins to Venus' 11 in the siblings' career record, meeting in four Wimbledon finals and a semi-final.
While Serena is gunning for the calendar grand slam, Venus is searching her first Wimbledon title since 2008.
Younger sister Serena hailed Venus as a "pioneer" for both the sport and women's rights.
"Where do I start?" asked Serena, when asked to chart Venus' tennis legacy. "She's done so much for this sport.
"It's just been amazing for me to follow in her footsteps in terms of getting equal prize money here, just stepping up to the plate and being that person."
Whatever happens on Monday, Serena admitted the impact will not sink in while the pair are still chasing yet more grand slam glory, conceding "that's pretty crazy" that the duo first took each other on professionally almost two decades ago.
"That's a question you have to ask me in four or five years I think," said Serena when asked how special it would be to clash for the first time in six years.
Grand slam duels have never sat easy with the Williams sisters' family bonds, and Serena admitted time has not eased those conflicting emotions.
"It's unfortunate that it's so soon, but we're going to do the best that we can," she said of Monday's match-up.
"She's my sister today, she's my sister next week, she's my sister next year: I think that's a little more important than a match.
"We'll leave everything out on the court. When it's done we'll go back to regular life. I think it will be a really good match, she's playing so well.
"I'm practising next to her every day and I'm in awe of how she's doing. It's a little frustrating because I know I have to play her.
"I just don't know how I'm going to do, to be honest. I'm playing the toughest player I've played in women's tennis."
Source: PA
