A fifth all-Williams women's singles final at Wimbledon remains a possibility after the two siblings each progressed to the last eight on a day that saw third seed Agnieskza Radwanska dramatically beaten.
Reigning champion Serena - a six-time champion at the All England Club - and five-time winner Venus claimed straight-sets victories in matches that were briefly interrupted, the former reeling off nine games in a row to beat Svetlana Kuznetsova 7-5 6-0 on Centre Court.
There were also wins on Monday for Angelique Kerber and Simona Halep, the respective fourth and fifth seeds who will now face each other.
However, Radwanska's tournament came to an end as Dominika Cibulkova - who may yet be forced to postpone the wedding she has scheduled for Saturday - prevailed 6-3 5-7 9-7 in arguably the match of the tournament to date.
Yaroslava Shvedova, Elena Vesnina and Anastasia Pavlyuchenkova - Serena's next opponent - were the other players to reach the quarter-finals, which take place on Tuesday.
VENUS DETERMINED TO KICK ON
A 7-6 (7-3) 6-4 triumph over Carla Suarez Navarro ensured Venus Williams is through to the quarters at Wimbledon for the first time since 2010, but the 36-year-old hopes she is not finished yet.
"Yeah, it's been a few years. I missed a year or two. But I've been here before. I'm not, like, a deer in the headlights," said Williams.
"Of course, I want more. That's what anybody would want in a quarter-final."
Asked how her current game compares to when she last made the final at SW19 seven years ago, Williams replied: "Let's hope I can get to that level I was in '09. That means, hey, finals time."
SUPER CIBULKOVA COMES THROUGH 'TOUGHEST MATCH'
Cibulkova is no stranger to the latter stages of a grand slam and reached the Australian Open final in 2014.
However, the Slovakian described her gruelling three-hour encounter with Radwanska, which was followed by a standing ovation on No.3 Court, as "the most physically tough match in my whole career".
"It was just so tough to go through, but I was just fighting for every ball," said Cibulkova, who spurned a match point in the second set.
"I can't describe how tough it was."
KERBER, HALEP EARN CONTRASTING WINS
Australian Open champion Kerber was Monday's most convincing winner, dropping just four games in a thrashing of Japan's Misaki Doi.
Yet Kerber's quarter-final opponent, Halep, had to work much harder to see off ninth seed Madison Keys, the Romanian eventually triumphing 6-7 (5-7) 6-4 6-3 as her opponent struggled with cramp in the final set.
Looking ahead to her clash with Kerber, Halep said: "I know it's going to be tough. She has had a good year so far.
"I am confident. I have to be. I am playing well."
Halep and Kerber will kick off proceedings on Centre Court on Tuesday, with Serena Williams' match against Pavlyuchenkova following. Venus and Shvedova will be the first players on No.1 Court before Cibulkova takes on Vesnina.