Both Williams sisters reached the quarter-finals at Wimbledon, while Andy Murray blew away Nick Kyrgios to also make the final eight.
The 19th-seeded Slovakian Dominika Cibulkova provided the day's biggest upset, beating third seed Agnieszka Radwanska of Poland 6-3 5-7 9-7 21-19.
World No.2 Murray withstood the challenge of Kyrgios, sweeping aside the mercurial Australian 7-5 6-1 6-4 on Centre Court to reach his ninth straight Wimbledon quarter-final.
Andy Murray celebrates beating Australia's Nick Kyrgios Photo: AFP
For much of a pulsating first set 15th seed Kyrgios had the edge, however, thudding down lightning fast serves that the second-seeded Scot struggled to reach, let alone control.
Murray's serve, meanwhile, was misfiring and, under darkening skies and roared on by a partisan crowd, he had to dig deep to stay on terms with the Australian.
The set and the match turned in the 12th game, when a combination of Kyrgios errors and two inspired Murray backhands presented the Scot with three break points. Kyrgios saved the first two with booming serves but Murray converted the third when the Australian netted a forehand volley.
Thereafter Kyrgios's focus and intensity wavered, the Briton breaking him twice in a second set that flew by in 26 minutes. He broke once more in the third, closing out the contest with an ace on his third match point.
Murray, the top remaining seed, will face swashbuckling Frenchman Jo-Wilfried Tsonga, the 12th seed, in the quarter-finals.
Tsonga said he was confident he could beat Murray after he won his fourth-round match when fellow Frenchman Richard Gasquet retired with a back injury.
Tsonga, who clinched a marathon match at the weekend against John Isner 19-17 in the final set, was 4-2 up in the first set against No.7 seed Gasquet when the match was ended.
The 31-year-old said the tie with Murray held no fear for him after the epic Isner encounter.
"That's why tennis is great. Two days ago I was 5-5 in the third set, 15-40 against me, two sets to love down, and I came back. I'm still alive in this tournament," Tsonga, seeded 12, said.
"Everything can happen in tennis. I'm very confident of my capacity to play great tennis and beat players like Andy."
Serena serene in seeing off Russian Kuznetsova
World number one Serena Williams kept her bid for a record-equalling 22nd grand slam title on track, overpowering Russian 13th seed Svetlana Kuznetsova in a 7-5 6-0 rout.
Kuznetsova, a double grand slam winner and three-times Wimbledon quarter-finalist, beat Williams on a hardcourt at the Miami Open in March.
Serena Williams (L) shakes hands after beating Svetlana Kuznetsova Photo: AFP
But on this occasion the six-times Wimbledon champion was too hot to handle, beginning the match as if late for an Independence Day appointment, serving a succession of aces and then hitting a brace of groundstroke winners, one off each wing, to break the Russian in the fourth game.
Kuznetsova battled her way back, varying her pace by mixing in slices and drop shots on a surface on which both players at times struggled to keep their footing.
Williams - bidding to equal Steffi Graf's professional-era record of 22 grand slam singles titles - eventually shaded a first set that featured five breaks of serve and a break for drizzle when the Centre Court roof was closed.
She ran though her opponent without losing another game after play resumed at 5-5 in the first set.
The defending champion and number one seed faces another Russian, Anastasia Pavlyuchenkova, in the quarter-finals, where she was joined for the first time since 2010 by older sister Venus.
"It's great," the younger Williams said. "She's been doing a lot of improvements. That's been really good for her and super encouraging for me."
Venus edges Suarez Navarro
Venus Williams strode to her victory against a scampering Carla Suarez Navarro, beating the Spaniard 7-6 6-4.
Williams, with five Wimbledon crowns to her name, used her 20 years of experience on the WTA Tour to overcome early sluggishness, a rain break and a busy opponent.
The oldest woman in the draw at 36, Williams looked out of sorts when she arrived on Court One, losing the first three games of the contest.
She pulled back to a tiebreak but had to run off court for half an hour because of a rain shower - a feature of this year's tournament.
"I thought: Oh no not again," eighth seed Williams said. "It was hard... I was dismayed.
"I just tried to stay focused and she gave me a few points and that saw me through."
Another day at the office...! pic.twitter.com/Uj1A80RiDI
— Venus Williams (@Venuseswilliams) July 4, 2016
Other winners included seven-times Wimbledon champion Roger Federer, sixth seeded Canadian Milos Raonic and US 28th seed Sam Querrey.
Federer eased past American Steve Johnson 6-2 6-3 7-5 to draw level with Martina Navratilova on a record 306 grand slam singles match wins.
The Swiss star will play Croatian Marin Cilic in the quarter-finals after the ninth seeded Croatian beat fifth seed Kei Nishikori of Japan 6-1 5-1, with Nishikori retiring.
Raonic beat 11th seed David Goffin of Belgium 4-6 3-6 6-4 6-4 6-4 to book a match against Querrey, who beat Nicolas Mahut of France 6-4 7-6 6-4.
Meanwhile another Frenchman, Lucas Pouille, looked dumbfounded at his 6-4 4-6 3-6 6-4 10-8 win over fellow young gun Bernard Tomic.
Pouille had never before won a five-set match at ATP Tour level and the 22-year-old had never beaten a seeded player at a grand slam.
After coolly sealing the near three-hour battle with the 23-year-old Australian 19th seed by punching down two aces, Pouille fell on his back and then sat looking stunned on his chair, soaking up the applause.
He had already bested his major performance by reaching the Wimbledon last 16 when downing Argentine Juan Martin del Potro - as well as far surpassing his own expectations.
"Before the tournament, (it) was to win one match on grass. Yeah, now, of course, I'm very happy, very emotional with the win today," the 32nd seed told reporters.
He and Tomic were two of the four players aged 23 and under in the fourth round - the most at Wimbledon since 2010, when the youth wing included Murray and now world No.1 Novak Djokovic.
New Zealander Artem Sitak's mixed doubles campaign ended with a second round loss alongside the German Laura Siegemund to the powerful veteran combination of India's Leander Paes and Swiss great Martina Hingis.
The 16th seeds won 6-4 6-4.
Another to progress was fifth seed Simona Halep of Romania, who beat ninth-seeded American Madison Keys 6-7 6-4 6-3.
-Reuters
