Wimbledon 2015: Venus Williams backs Serena to be the cream of the crop
Venus Williams believes her "ultimate champion" sister Serena is on course to become the greatest player in the history of women's tennis.
Serena bludgeoned mercilessly past older sister Venus to reach her 11th Wimbledon quarter-final on Monday, as the two five-time champions locked horns for the first time in six years at SW19.
Reigning Australian and French Open champion Serena edged a step closer to the calendar grand slam by seeing off her in-form 35-year-old sister, to book a last-eight battle with Victoria Azarena.
The 33-year-old boasts 20 grand slam titles but still trails Steffi Graf's 22 and Margaret Court's 24, leaving Venus claiming it is too early to anoint the younger Williams sister the best of all time.
"I don't think she's done, so we'll see what more she does," said veteran Venus, who expects to return to compete at Wimbledon next year.
"I don't think she would call herself the greatest player of all time because she respects everyone else and the accomplishments they've made.
"But the level she's playing at is unprecedented. I can say that with confidence. So make what you will of it.
"Then when it's a wrap, it will be easier to make labels and not offend anybody."
World number 16 Venus threw powerful serving, rangy ground shots and crafty net play at her top seed sister, only for world number one Serena to storm to victory 6-4 6-3.
Some 17 years after the inseparable siblings first met in the professional arena, neither Williams asked or offered any quarter.
Serena's switch to coach Patrick Mouratoglou in 2012 has yielded seven grand slam titles so far, with father Richard Williams not in attendance at Wimbledon since.
Where once there were wild accusations of the Williams' domineering dad-coach preordaining results between his daughters, here there was only an all-out scrap.
Venus may struggle to generate many more chances for an eighth grand slam crown, but threw her considerable weight of opinion behind sister Serena's claims to this year's and a sixth Wimbledon title.
"Absolutely," volunteered Venus when asked if Serena is in championship-winning form.
"Her serve is consistent, she's taking her opportunities; minimal errors.
"It's going to be tough for anyone to defeat her.
"Maybe she didn't have her best day on the last round (against Britain's Heather Watson), but she found a way to win against an inspired opponent.
"That's what it takes to win in these championships, even when you're not at the level you want to be at.
"She's a champion. What else could you say about that - the ultimate champion.
"When we were kids I don't think we thought about any limits.
"When you're a kid, you don't think about limits, you dream.
"That's how it's happening for her now, dreams are coming true.
"We've played a lot of years and we've tried to be entertaining.
"We won't be playing forever, but clearly we're playing at a very high level now.
"When that moment is over, it will be over. It's not now."
Serena set aside any pangs of guilt at robbing Venus - who has battled auto-immune illness in recent years - of a tilt at a first grand slam title since 2008 to progress in imperious fashion.
After swatting aside her sister and "best friend in the world", Serena vowed it would not be the last time the two meet on London's matchless grass courts.
"I just really was enjoying the moment out there," said Serena.
"It was such a great vibe, such a great situation to be in, when we had been both so young and dreaming of coming to Wimbledon.
"Not only did we fulfil our dreams, we both won it five times. That's pretty amazing.
"I just had an opportunity to reflect on that.
"We're both playing really well. So I think this opportunity could come often again.
"Hopefully it will come a little later in the tournament, but I definitely think it could present itself again.
"Venus is playing great.
"I don't enjoy playing her in general so early at any type of tournament.
"I'm totally okay if it's at a later stage.
"That's just how it worked out.
"I always say I wouldn't be the player I am today if it wasn't for Venus.
"Just having an opportunity to watch her win matches, watch her go to the top, and me wanting to be there because she was there.
"But for me, I feel like my tournament has finally begun.
"This is where I feel really comfortable in a grand slam."