London - Roger Federer, Rafael Nadal and Novak Djokovic, with 14 Wimbledon titles between them, dominate 'Manic Monday' at the All England Club with the 'Big Three' still standing while weary rivals have again flattered to deceive.
Eight-time champion Federer, four-time winner Djokovic and Nadal, a double champion, all play last 16 ties against opponents who have never progressed this far before.
Federer, the second seed, tackles Italy's world No 20 Matteo Berrettini in what will be the Swiss great's record 17th fourth round appearance at the All England Club.
"I don't know him very well, so that makes it a bit more tricky," said Federer, chasing a 21st Grand Slam title.
"I saw him play a little bit in Halle (where he made the semi-finals). Saw his run, of course, in Stuttgart (which Berrettini won).
"Now he's backing it up here again. That's not easy to do, especially when you're sort of newer on the tour."
Nadal, the champion in 2008 and 2010, also has an unexpected opponent in the shape of world No 69 Joao Sousa, the first Portuguese player to reach the fourth round at Wimbledon.
Nadal has a 2-0 career advantage over the 30-year-old Sousa, with both wins coming on clay.
"He's a super dangerous opponent against everybody. He is very quick, has a very good physical performance," said Nadal, looking to back up his 12th Roland Garros title last month with a third Wimbledon.
Djokovic insists he will not be complacent about his chances of reaching the final for the sixth time.
The highest seed that the world No 1 can face before the final is number 15 Milos Raonic, the 2016 runner-up from Canada.
But first up for the defending champion and 16-time major winner is 21-year-old Ugo Humbert from France who is playing in his first Wimbledon.
"There were a lot of top seeds that went out in early rounds in Wimbledon," said Djokovic.
"That's why these kind of tournaments are regarded as the most important events where you always come out with your best game."
Until this year, world No 66 Humbert had never played a grass court match on grass either as a junior or professional.
However, he has knocked out two seeds to get this far.
He saw off compatriot Gael Monfils, the 16th seed, through a first round retirement and then 19th seeded Canadian Felix Auger-Aliassime in straight sets in the last 32.
Should Djokovic emerge triumphant, he would face either Belgian 21st seed David Goffin or Spanish veteran Fernando Verdasco in what would be his 11th quarter-final at the tournament.
Raonic, beaten by Andy Murray in the 2016 final, has made the quarter-finals in the last two years.
So far at this Wimbledon, he has fired 59 aces across three rounds and dropped serve just once.
Raonic tackles Argentine 26th seed Guido Pella who has reached the last 16 at a Slam for the first time - at the 20th attempt.
The 29-year-old Pella knocked out last year's runner-up and fourth seed Kevin Anderson in the third round.
Roberto Bautista Agut, the Spanish 23rd seed, faces French 28th seed Benoit Paire with both men aiming to make the quarter-finals for the first time.
That would have been an unthinkable achievement for the volatile Frenchman just five years ago when he said he "hated Wimbledon... the tournament displeases me greatly".
Monday's other ties see 2017 semi-finalist Sam Querrey face last-16 debutant and US compatriot Tennys Sandgren.
Japan's Kei Nishikori, a quarter-finalist in 2018, tackles Mikhail Kukushkin of Kazakhstan.
Nishikori recorded his 400th tour victory when he beat Steve Johnson in Saturday's third round.
Wimbledon men's singles last 16 line up (x denotes seeded player):
Novak Djokovic (SRB x1) v Ugo Humbert (FRA)
David Goffin (BEL x21) v Fernando Verdasco (ESP)
Guido Pella (ARG x26) v Milos Raonic (CAN x15)
Roberto Bautista Agut (ESP x23) Benoit Paire (FRA x28)
Sam Querrey (USA) v Tennys Sandgren (USA)
Joao Sousa (POR) v Rafael Nadal (ESP x3)
Kei Nishikori (JPN x8) v Mikhail Kukushkin (KAZ)
Matteo Berrettini (ITA x17) v Roger Federer (SUI x2)